/* ========================================================================
   RegraDE3 — Premium Calculadora Regra de Três
   Design System: Dark Luxury · Glassmorphism · Indigo/Violet/Pink
   ======================================================================== */

/* --- CSS Custom Properties --- */
:root {
    /* Brand Gradient — Indigo to Violet to Pink */
    --grad-start: #818cf8;
    --grad-mid: #c084fc;
    --grad-end: #f472b6;
    --accent-1: #818cf8;
    --accent-2: #c084fc;
    --accent-3: #f472b6;

    /* Surfaces */
    --bg-body: #06060e;
    --bg-surface: rgba(8, 8, 20, 0.65);
    --bg-card: rgba(10, 10, 28, 0.55);
    --bg-card-hover: rgba(16, 14, 40, 0.7);
    --bg-input: rgba(10, 8, 24, 0.8);
    --border-subtle: rgba(129, 140, 248, 0.08);
    --border-glow: rgba(192, 132, 252, 0.25);

    /* Text */
    --text-primary: #e8eaf8;
    --text-secondary: #929ab8;
    --text-tertiary: #525870;
    --text-accent: #818cf8;

    /* Layout */
    --container-max: 1200px;
    --section-gap: 120px;
    --radius-sm: 10px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --radius-xl: 32px;

    /* Typography */
    --font-display: 'Space Grotesk', sans-serif;
    --font-body: 'Inter', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;

    /* Transitions */
    --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
    --transition-fast: 0.2s var(--ease-out-expo);
    --transition-med: 0.4s var(--ease-out-expo);
    --transition-slow: 0.7s var(--ease-out-expo);
}

/* --- Reset & Base --- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-body);
    background: var(--bg-body);
    color: var(--text-primary);
    line-height: 1.7;
    overflow-x: hidden;
    position: relative;
}

::selection {
    background: rgba(192, 132, 252, 0.25);
    color: #fff;
}

a { color: var(--text-accent); text-decoration: none; transition: color var(--transition-fast); }
a:hover { color: var(--accent-2); }

img { max-width: 100%; display: block; }

/* --- Ambient Background --- */
.ambient-bg {
    position: fixed;
    inset: 0;
    z-index: -1;
    overflow: hidden;
    pointer-events: none;
}

.orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(130px);
    opacity: 0.22;
    animation: orbFloat 20s ease-in-out infinite;
}

.orb-1 {
    width: 650px; height: 650px;
    background: radial-gradient(circle, var(--accent-1), transparent 70%);
    top: -12%; left: -10%;
    animation-duration: 24s;
}

.orb-2 {
    width: 550px; height: 550px;
    background: radial-gradient(circle, var(--accent-3), transparent 70%);
    bottom: 8%; right: -6%;
    animation-duration: 28s;
    animation-delay: -8s;
}

.orb-3 {
    width: 450px; height: 450px;
    background: radial-gradient(circle, var(--accent-2), transparent 70%);
    top: 45%; left: 35%;
    animation-duration: 32s;
    animation-delay: -14s;
}

@keyframes orbFloat {
    0%, 100% { transform: translate(0, 0) scale(1); }
    25%      { transform: translate(60px, -40px) scale(1.08); }
    50%      { transform: translate(-30px, 50px) scale(0.95); }
    75%      { transform: translate(-50px, -30px) scale(1.05); }
}

.grid-overlay {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(192, 132, 252, 0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(192, 132, 252, 0.02) 1px, transparent 1px);
    background-size: 60px 60px;
    mask-image: radial-gradient(ellipse 70% 60% at 50% 50%, black, transparent);
}

/* --- Navigation --- */
.navbar {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 1000;
    padding: 16px 0;
    transition: background var(--transition-med), box-shadow var(--transition-med), padding var(--transition-med);
}

.navbar.scrolled {
    background: rgba(6, 6, 14, 0.88);
    backdrop-filter: blur(20px) saturate(1.4);
    -webkit-backdrop-filter: blur(20px) saturate(1.4);
    box-shadow: 0 1px 0 var(--border-subtle), 0 8px 32px rgba(0, 0, 0, 0.4);
    padding: 10px 0;
}

.nav-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 32px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: var(--text-primary);
}

.logo-icon {
    width: 40px; height: 40px;
    flex-shrink: 0;
}

.logo-icon svg { width: 100%; height: 100%; }

.logo-text {
    font-family: var(--font-display);
    font-weight: 700;
    font-size: 1.25rem;
    letter-spacing: -0.02em;
}

.logo-accent {
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2), var(--accent-3));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link {
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
    text-decoration: none;
}

.nav-link:hover {
    color: var(--text-primary);
    background: rgba(192, 132, 252, 0.08);
}

.nav-cta {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 22px;
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2), var(--accent-3));
    color: #06060e;
    font-weight: 600;
    font-size: 0.875rem;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
    font-family: var(--font-body);
}

.nav-cta:hover {
    transform: translateY(-1px);
    box-shadow: 0 8px 24px rgba(192, 132, 252, 0.3);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.mobile-menu-btn span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all var(--transition-fast);
}

/* --- Gradient Text --- */
.gradient-text {
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2), var(--accent-3));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* --- Hero Section --- */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 120px 0 80px;
    position: relative;
}

.hero-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 32px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: center;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: rgba(129, 140, 248, 0.06);
    border: 1px solid rgba(129, 140, 248, 0.12);
    color: var(--accent-1);
    padding: 8px 20px;
    border-radius: 100px;
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    margin-bottom: 24px;
    animation: fadeInUp 0.8s var(--ease-out-expo) both;
}

.badge-dot {
    width: 8px; height: 8px;
    background: var(--accent-1);
    border-radius: 50%;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.5; transform: scale(0.8); }
}

.hero-title {
    font-family: var(--font-display);
    font-size: clamp(2.8rem, 5.5vw, 4.5rem);
    font-weight: 800;
    line-height: 1.08;
    letter-spacing: -0.03em;
    margin-bottom: 24px;
    animation: fadeInUp 0.8s 0.1s var(--ease-out-expo) both;
}

.hero-description {
    font-size: 1.1rem;
    line-height: 1.75;
    color: var(--text-secondary);
    max-width: 520px;
    margin-bottom: 36px;
    animation: fadeInUp 0.8s 0.2s var(--ease-out-expo) both;
}

.hero-actions {
    display: flex;
    gap: 16px;
    margin-bottom: 48px;
    animation: fadeInUp 0.8s 0.3s var(--ease-out-expo) both;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 32px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.95rem;
    font-family: var(--font-body);
    cursor: pointer;
    transition: all var(--transition-fast);
    border: none;
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2), var(--accent-3));
    color: #06060e;
    box-shadow: 0 4px 16px rgba(192, 132, 252, 0.25);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 32px rgba(192, 132, 252, 0.4);
    color: #06060e;
}

.btn-secondary {
    background: rgba(192, 132, 252, 0.08);
    color: var(--text-primary);
    border: 1px solid rgba(192, 132, 252, 0.2);
}

.btn-secondary:hover {
    background: rgba(192, 132, 252, 0.14);
    border-color: rgba(192, 132, 252, 0.35);
    color: var(--text-primary);
}

.btn-full {
    width: 100%;
    justify-content: center;
}

.hero-stats {
    display: flex;
    align-items: center;
    gap: 32px;
    animation: fadeInUp 0.8s 0.4s var(--ease-out-expo) both;
}

.hero-stat {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.stat-number {
    font-family: var(--font-display);
    font-size: 2rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2), var(--accent-3));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 0.8rem;
    color: var(--text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-weight: 500;
}

.hero-stat-divider {
    width: 1px;
    height: 40px;
    background: linear-gradient(to bottom, transparent, var(--border-glow), transparent);
}

.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
    animation: fadeInUp 0.8s 0.3s var(--ease-out-expo) both;
}

.hero-equation-container {
    position: relative;
    width: 500px;
    height: 500px;
}

.hero-equation-container canvas {
    width: 100%;
    height: 100%;
}

.equation-glow {
    position: absolute;
    inset: 0;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(192, 132, 252, 0.1), transparent 60%);
    pointer-events: none;
}

.hero-scroll-indicator {
    display: flex;
    align-items: center;
    gap: 8px;
    justify-content: center;
    margin-top: 32px;
    color: var(--text-tertiary);
    font-size: 0.8rem;
    animation: fadeInUp 1s 0.6s var(--ease-out-expo) both;
}

.scroll-arrow {
    animation: scrollBounce 2s ease-in-out infinite;
}

@keyframes scrollBounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(6px); }
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(24px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* --- Section Common --- */
.section-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 32px;
}

.section-header {
    text-align: center;
    margin-bottom: 64px;
}

.section-tag {
    display: inline-block;
    background: rgba(129, 140, 248, 0.06);
    border: 1px solid rgba(129, 140, 248, 0.12);
    color: var(--accent-1);
    padding: 6px 18px;
    border-radius: 100px;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    margin-bottom: 20px;
}

.section-title {
    font-family: var(--font-display);
    font-size: clamp(2rem, 4vw, 2.8rem);
    font-weight: 800;
    line-height: 1.15;
    letter-spacing: -0.02em;
    margin-bottom: 16px;
}

.section-subtitle {
    color: var(--text-secondary);
    font-size: 1.05rem;
    max-width: 640px;
    margin: 0 auto;
    line-height: 1.7;
}

/* --- How It Works --- */
.how-it-works {
    padding: var(--section-gap) 0;
}

.steps-grid {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
}

.step-card {
    flex: 1;
    max-width: 300px;
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: 36px 28px;
    text-align: center;
    position: relative;
    backdrop-filter: blur(12px);
    transition: all var(--transition-med);
}

.step-card::before {
    content: attr(data-step);
    position: absolute;
    top: -14px;
    left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2), var(--accent-3));
    color: #06060e;
    font-family: var(--font-mono);
    font-weight: 700;
    font-size: 0.75rem;
    padding: 4px 14px;
    border-radius: 100px;
}

.step-card:hover {
    border-color: var(--border-glow);
    background: var(--bg-card-hover);
    transform: translateY(-4px);
    box-shadow: 0 16px 48px rgba(192, 132, 252, 0.08);
}

.step-icon {
    width: 56px; height: 56px;
    margin: 0 auto 20px;
    color: var(--accent-1);
}

.step-icon svg { width: 100%; height: 100%; }

.step-title {
    font-family: var(--font-display);
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 10px;
}

.step-desc {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.6;
}

.step-connector {
    width: 80px;
    flex-shrink: 0;
}

.step-connector svg { width: 100%; height: auto; }

/* --- How It Works Section (Homepage HIW) --- */
.how-it-works-section {
    padding: var(--section-gap) 0;
    position: relative;
}

.hiw-intro-text {
    max-width: 820px;
    margin: -32px auto 56px;
    text-align: center;
}

.hiw-intro-text p {
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.8;
}

.hiw-intro-text strong {
    color: var(--text-primary);
    font-weight: 600;
}

/* Steps Grid */
.hiw-steps-grid {
    display: flex;
    align-items: stretch;
    justify-content: center;
    gap: 0;
    margin-bottom: 56px;
}

.hiw-step-card {
    flex: 1;
    max-width: 320px;
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-xl);
    padding: 40px 28px 36px;
    text-align: center;
    position: relative;
    backdrop-filter: blur(12px);
    transition: all var(--transition-med);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.hiw-step-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-1), var(--accent-2), var(--accent-3));
    border-radius: var(--radius-xl) var(--radius-xl) 0 0;
    opacity: 0;
    transition: opacity var(--transition-med);
}

.hiw-step-card:hover {
    border-color: var(--border-glow);
    background: var(--bg-card-hover);
    transform: translateY(-6px);
    box-shadow:
        0 20px 60px rgba(192, 132, 252, 0.08),
        0 0 0 1px rgba(192, 132, 252, 0.12);
}

.hiw-step-card:hover::before {
    opacity: 1;
}

/* Step Number Badge */
.hiw-step-number {
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2), var(--accent-3));
    color: #06060e;
    font-family: var(--font-display);
    font-weight: 800;
    font-size: 0.95rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    position: relative;
    z-index: 1;
    box-shadow: 0 4px 16px rgba(192, 132, 252, 0.25);
}

/* Step Visual (SVG icon container) */
.hiw-step-visual {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(129, 140, 248, 0.04);
    border: 1px solid rgba(129, 140, 248, 0.08);
    border-radius: var(--radius-lg);
    transition: all var(--transition-med);
}

.hiw-step-card:hover .hiw-step-visual {
    background: rgba(129, 140, 248, 0.08);
    border-color: rgba(129, 140, 248, 0.2);
    box-shadow: 0 0 24px rgba(129, 140, 248, 0.1);
    transform: scale(1.05);
}

.hiw-step-visual svg {
    width: 64px;
    height: 64px;
}

/* Step Text */
.hiw-step-title {
    font-family: var(--font-display);
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 10px;
    letter-spacing: -0.01em;
}

.hiw-step-desc {
    color: var(--text-secondary);
    font-size: 0.88rem;
    line-height: 1.65;
}

/* Step Connector (arrow between cards) */
.hiw-step-connector {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 56px;
    flex-shrink: 0;
    padding-top: 40px;
}

.hiw-step-connector svg {
    width: 40px;
    height: auto;
    opacity: 0.7;
}

/* Example Card */
.hiw-example-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-xl);
    padding: 40px;
    margin-bottom: 56px;
    position: relative;
    overflow: hidden;
    backdrop-filter: blur(12px);
}

.hiw-example-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-2), var(--accent-3));
}

.hiw-example-badge {
    display: inline-block;
    background: rgba(192, 132, 252, 0.1);
    color: var(--accent-2);
    border: 1px solid rgba(192, 132, 252, 0.2);
    padding: 6px 18px;
    border-radius: 100px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin-bottom: 24px;
}

.hiw-example-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: start;
}

.hiw-example-q {
    font-size: 1.1rem;
    line-height: 1.7;
    color: var(--text-primary);
    font-weight: 500;
    padding-right: 16px;
    border-right: 2px solid rgba(192, 132, 252, 0.15);
}

.hiw-example-solution {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.hiw-example-step {
    display: flex;
    align-items: baseline;
    gap: 10px;
    padding: 10px 16px;
    background: rgba(255, 255, 255, 0.02);
    border-radius: var(--radius-sm);
}

.hiw-example-label {
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--accent-2);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    flex-shrink: 0;
    min-width: 65px;
}

.hiw-example-value {
    color: var(--text-secondary);
    font-size: 0.92rem;
    font-family: var(--font-mono);
    line-height: 1.5;
}

.hiw-example-result {
    background: rgba(129, 140, 248, 0.06);
    border: 1px solid rgba(129, 140, 248, 0.12);
}

.hiw-example-value-highlight {
    color: var(--accent-1);
    font-weight: 700;
    font-size: 1rem;
}

/* Features Grid */
.hiw-features-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.hiw-feature-item {
    display: flex;
    gap: 20px;
    padding: 28px;
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    transition: all var(--transition-med);
    position: relative;
    overflow: hidden;
}

.hiw-feature-item::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(to right, var(--accent-1), var(--accent-2), var(--accent-3));
    opacity: 0;
    transition: opacity var(--transition-med);
}

.hiw-feature-item:hover {
    border-color: var(--border-glow);
    background: var(--bg-card-hover);
    transform: translateY(-3px);
    box-shadow: 0 12px 40px rgba(192, 132, 252, 0.06);
}

.hiw-feature-item:hover::after {
    opacity: 1;
}

.hiw-feature-icon {
    width: 48px;
    height: 48px;
    flex-shrink: 0;
    background: rgba(129, 140, 248, 0.06);
    border: 1px solid rgba(129, 140, 248, 0.15);
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-1);
    transition: all var(--transition-med);
}

.hiw-feature-item:hover .hiw-feature-icon {
    background: rgba(129, 140, 248, 0.12);
    border-color: rgba(129, 140, 248, 0.3);
    box-shadow: 0 0 20px rgba(129, 140, 248, 0.12);
}

.hiw-feature-text {
    flex: 1;
    min-width: 0;
}

.hiw-feature-title {
    font-family: var(--font-display);
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
    letter-spacing: -0.01em;
}

.hiw-feature-text p:not(.hiw-feature-title) {
    color: var(--text-secondary);
    font-size: 0.88rem;
    line-height: 1.65;
}

/* HIW Responsive */
@media (max-width: 1024px) {
    .hiw-steps-grid {
        flex-direction: column;
        align-items: center;
        gap: 0;
    }

    .hiw-step-card {
        max-width: 480px;
        width: 100%;
    }

    .hiw-step-connector {
        transform: rotate(90deg);
        width: 40px;
        padding-top: 0;
        height: 40px;
    }

    .hiw-example-content {
        grid-template-columns: 1fr;
        gap: 24px;
    }

    .hiw-example-q {
        border-right: none;
        border-bottom: 2px solid rgba(192, 132, 252, 0.15);
        padding-right: 0;
        padding-bottom: 20px;
    }

    .hiw-features-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .hiw-step-card {
        padding: 32px 22px 28px;
    }

    .hiw-example-card {
        padding: 28px;
    }

    .hiw-feature-item {
        flex-direction: column;
        gap: 16px;
    }
}

/* --- Calculator Section --- */
.calculator-section {
    padding: var(--section-gap) 0 32px;
}

.calculator-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 32px;
}

.calc-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: 32px;
    backdrop-filter: blur(12px);
}

.calc-card-title {
    display: flex;
    align-items: center;
    gap: 10px;
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 28px;
    color: var(--text-primary);
}

.calc-card-title svg { color: var(--accent-1); flex-shrink: 0; }

/* --- Converter Form --- */
.converter-form {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-label {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.form-input-wrap {
    position: relative;
}

.form-input {
    width: 100%;
    padding: 14px 18px;
    background: var(--bg-input);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 1.1rem;
    font-family: var(--font-mono);
    font-weight: 500;
    transition: all var(--transition-fast);
    outline: none;
}

.form-input:focus {
    border-color: var(--accent-2);
    box-shadow: 0 0 0 3px rgba(192, 132, 252, 0.12);
}

.form-input::placeholder { color: var(--text-tertiary); font-family: var(--font-body); }

.form-unit {
    position: absolute;
    right: 14px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--accent-1);
    font-family: var(--font-mono);
    font-weight: 600;
    font-size: 0.85rem;
    pointer-events: none;
    background: var(--bg-input);
    padding-left: 8px;
}

.form-select {
    width: 100%;
    padding: 14px 18px;
    background: var(--bg-input);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 0.95rem;
    font-family: var(--font-body);
    cursor: pointer;
    outline: none;
    transition: all var(--transition-fast);
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg width='12' height='8' viewBox='0 0 12 8' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1.5L6 6.5L11 1.5' stroke='%23929ab8' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 16px center;
    padding-right: 40px;
}

.form-select:focus {
    border-color: var(--accent-2);
    box-shadow: 0 0 0 3px rgba(192, 132, 252, 0.12);
}

.form-select option { background: #0a0a1c; color: var(--text-primary); }

/* --- Proportion Grid --- */
.proportion-grid {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 16px;
    align-items: center;
}

.proportion-side {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.proportion-label {
    font-family: var(--font-display);
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--accent-2);
    text-align: center;
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.proportion-connector {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 20px 8px;
}

.connector-line {
    width: 2px;
    height: 30px;
    background: linear-gradient(to bottom, var(--accent-1), var(--accent-3));
    opacity: 0.3;
}

.connector-symbol {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2), var(--accent-3));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.result-field .form-input {
    background: rgba(129, 140, 248, 0.06);
    border-color: rgba(129, 140, 248, 0.2);
    color: var(--accent-1);
    font-weight: 700;
    font-size: 1.2rem;
}

/* --- Result Display --- */
.result-container {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: 32px;
    backdrop-filter: blur(12px);
    height: 100%;
    display: flex;
    flex-direction: column;
}

.result-display {
    text-align: center;
    padding: 24px 0;
}

.result-big {
    font-family: var(--font-display);
    font-size: clamp(2.2rem, 4vw, 3rem);
    font-weight: 800;
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2), var(--accent-3));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 8px;
    word-break: break-all;
}

.result-label-text {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.result-divider {
    height: 1px;
    background: linear-gradient(to right, transparent, var(--border-glow), transparent);
    margin: 16px 0;
}

.result-formula-card {
    background: rgba(192, 132, 252, 0.04);
    border: 1px solid rgba(192, 132, 252, 0.1);
    border-radius: var(--radius-md);
    padding: 20px;
    margin-bottom: 16px;
}

.result-formula-card h4, .result-formula-card .result-formula-title {
    font-family: var(--font-display);
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--accent-1);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin-bottom: 12px;
}

.formula-line {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--text-secondary);
    padding: 4px 0;
    line-height: 1.6;
}

.formula-line strong {
    color: var(--text-primary);
    font-weight: 600;
}

.result-extras {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-top: auto;
}

.result-extra-item {
    background: rgba(192, 132, 252, 0.04);
    border: 1px solid rgba(192, 132, 252, 0.08);
    border-radius: var(--radius-sm);
    padding: 14px;
}

.extra-label {
    font-size: 0.72rem;
    color: var(--text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    font-weight: 600;
    margin-bottom: 4px;
}

.extra-value {
    font-family: var(--font-mono);
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.95rem;
}

/* --- Specialized Calculators Grid --- */
.specialized-section {
    padding: 32px 0 48px;
}

.spec-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

.spec-card {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 22px 24px;
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    text-decoration: none;
    color: var(--text-primary);
    transition: all var(--transition-med);
    position: relative;
    overflow: hidden;
}

.spec-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 2px;
    background: linear-gradient(to right, var(--accent-1), var(--accent-2), var(--accent-3));
    opacity: 0;
    transition: opacity var(--transition-med);
}

.spec-card:hover {
    border-color: var(--border-glow);
    background: var(--bg-card-hover);
    transform: translateY(-4px);
    box-shadow: 0 16px 48px rgba(192, 132, 252, 0.08);
    color: var(--text-primary);
}

.spec-card:hover::before { opacity: 1; }

.spec-icon {
    width: 52px; height: 52px;
    flex-shrink: 0;
    background: rgba(129, 140, 248, 0.06);
    border: 1px solid rgba(129, 140, 248, 0.15);
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-1);
    transition: all var(--transition-med);
}

.spec-card:hover .spec-icon {
    background: rgba(129, 140, 248, 0.12);
    border-color: rgba(129, 140, 248, 0.3);
    box-shadow: 0 0 20px rgba(129, 140, 248, 0.15);
}

.spec-icon-nursing {
    color: var(--accent-3);
    border-color: rgba(244, 114, 182, 0.15);
    background: rgba(244, 114, 182, 0.06);
}

.spec-card:hover .spec-icon-nursing {
    background: rgba(244, 114, 182, 0.12);
    border-color: rgba(244, 114, 182, 0.3);
    box-shadow: 0 0 20px rgba(244, 114, 182, 0.15);
}

.spec-info { flex: 1; min-width: 0; }

.spec-info h3, .spec-info .spec-title {
    font-family: var(--font-display);
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 4px;
    letter-spacing: -0.01em;
}

.spec-info p:not(.spec-title) {
    color: var(--text-secondary);
    font-size: 0.82rem;
    line-height: 1.5;
}

.spec-arrow {
    flex-shrink: 0;
    color: var(--text-tertiary);
    transition: all var(--transition-fast);
}

.spec-card:hover .spec-arrow {
    color: var(--accent-1);
    transform: translateX(3px);
}

@media (max-width: 768px) {
    .spec-grid { grid-template-columns: 1fr; }
}

/* --- Formula Section --- */
.formula-section {
    padding: 32px 0 64px;
}

.formula-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
    margin-bottom: 48px;
}

.formula-main-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-xl);
    padding: 40px;
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.formula-main-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-1), var(--accent-2));
}

.formula-main-card-inverse::before {
    background: linear-gradient(90deg, var(--accent-2), var(--accent-3));
}

.formula-card-badge {
    position: absolute;
    top: 24px;
    right: 24px;
    background: rgba(129, 140, 248, 0.1);
    color: var(--accent-1);
    border: 1px solid rgba(129, 140, 248, 0.2);
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.formula-card-badge-inverse {
    background: rgba(244, 114, 182, 0.1);
    color: var(--accent-3);
    border-color: rgba(244, 114, 182, 0.2);
}

.formula-card-header {
    text-align: center;
    margin-bottom: 32px;
    width: 100%;
}

.formula-card-header h3, .formula-card-header .formula-card-title {
    font-family: var(--font-display);
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.formula-card-header p:not(.formula-card-title) {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.formula-display {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 24px;
    margin-bottom: 24px;
    padding: 24px 48px;
    background: rgba(6, 6, 14, 0.5);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    width: 100%;
}

.formula-fraction {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    font-family: var(--font-display);
    font-size: 1.8rem;
    font-weight: 700;
}

.formula-fraction-sm {
    font-size: 1.4rem;
    gap: 4px;
}

.formula-num, .formula-den {
    color: var(--text-primary);
    line-height: 1;
}

.formula-den-x {
    color: var(--accent-2);
}

.formula-bar {
    width: 100%;
    min-width: 40px;
    height: 3px;
    background: var(--accent-1);
    border-radius: 2px;
}

.formula-bar-inverse {
    background: var(--accent-3);
}

.formula-equals {
    font-family: var(--font-display);
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--text-tertiary);
}

.formula-arrow-down {
    color: var(--text-tertiary);
    margin-bottom: 16px;
}

.formula-result-box {
    background: rgba(129, 140, 248, 0.05);
    border: 1px solid rgba(129, 140, 248, 0.15);
    border-radius: var(--radius-md);
    padding: 20px 40px;
    text-align: center;
    margin-bottom: 32px;
    width: 100%;
    position: relative;
}

.formula-result-box-inverse {
    background: rgba(244, 114, 182, 0.05);
    border-color: rgba(244, 114, 182, 0.15);
}

.formula-result-label {
    position: absolute;
    top: -10px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--bg-card);
    padding: 0 12px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--text-secondary);
    letter-spacing: 0.05em;
}

.formula-result-expr {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
}

.formula-x-highlight {
    font-family: var(--font-display);
    font-size: 2rem;
    font-weight: 800;
    color: var(--accent-2);
}

.formula-op {
    font-family: var(--font-display);
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text-secondary);
}

.formula-steps {
    width: 100%;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.formula-step {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px;
    background: rgba(255, 255, 255, 0.02);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.formula-step-num {
    width: 24px;
    height: 24px;
    background: rgba(192, 132, 252, 0.1);
    color: var(--accent-2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.8rem;
    flex-shrink: 0;
}

.formula-concepts {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.formula-concept {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: 24px;
    text-align: center;
}

.formula-concept-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto 16px;
    background: rgba(192, 132, 252, 0.08);
    color: var(--accent-2);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.formula-concept h4, .formula-concept .formula-concept-title {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.formula-concept p:not(.formula-concept-title) {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.5;
}

@media (max-width: 1024px) {
    .formula-grid { grid-template-columns: 1fr; }
    .formula-concepts { grid-template-columns: 1fr; }
}

/* --- Diagram Section --- */
.diagram-section {
    padding: 24px 0 20px;
}

.diagram-wrapper {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-xl);
    overflow: hidden;
    backdrop-filter: blur(12px);
}

.diagram-canvas-wrap {
    padding: 24px;
    display: flex;
    justify-content: center;
    min-height: 0;
}

.diagram-canvas-wrap canvas {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-md);
}

/* --- Conversion Table --- */
.table-section {
    padding: var(--section-gap) 0;
}

.table-wrap {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    overflow: hidden;
    backdrop-filter: blur(12px);
}

.table-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 24px 28px;
    border-bottom: 1px solid var(--border-subtle);
}

.table-header h3 {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 700;
}

.table-search {
    padding: 10px 16px;
    background: var(--bg-input);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 0.85rem;
    font-family: var(--font-body);
    outline: none;
    width: 240px;
    transition: all var(--transition-fast);
}

.table-search:focus {
    border-color: var(--accent-2);
    box-shadow: 0 0 0 3px rgba(192, 132, 252, 0.12);
}

.table-search::placeholder { color: var(--text-tertiary); }

.conversion-table {
    width: 100%;
    border-collapse: collapse;
}

.conversion-table thead th {
    padding: 14px 20px;
    text-align: left;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-tertiary);
    border-bottom: 1px solid var(--border-subtle);
    background: rgba(192, 132, 252, 0.03);
}

.conversion-table tbody td {
    padding: 14px 20px;
    font-size: 0.9rem;
    border-bottom: 1px solid rgba(192, 132, 252, 0.04);
    transition: background var(--transition-fast);
}

.conversion-table tbody tr:hover td {
    background: rgba(192, 132, 252, 0.04);
}

.conversion-table tbody tr { cursor: pointer; }

.conversion-table .mono {
    font-family: var(--font-mono);
    font-weight: 500;
    color: var(--accent-1);
}

/* --- Features --- */
.features {
    padding: var(--section-gap) 0;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: 32px 28px;
    transition: all var(--transition-med);
    position: relative;
    overflow: hidden;
}

.feature-card::after {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 2px;
    background: linear-gradient(to right, var(--accent-1), var(--accent-2), var(--accent-3));
    opacity: 0;
    transition: opacity var(--transition-med);
}

.feature-card:hover {
    border-color: var(--border-glow);
    background: var(--bg-card-hover);
    transform: translateY(-4px);
    box-shadow: 0 16px 48px rgba(192, 132, 252, 0.06);
}

.feature-card:hover::after { opacity: 1; }

.feature-icon {
    width: 52px; height: 52px;
    margin-bottom: 20px;
    color: var(--accent-1);
}

.feature-icon svg { width: 100%; height: 100%; }

.feature-card h3 {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 10px;
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.6;
}

/* --- FAQ --- */
.faq-section {
    padding: 28px 0 var(--section-gap);
}

.faq-grid {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.faq-item {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: all var(--transition-fast);
}

.faq-item:hover { border-color: var(--border-glow); }

.faq-question {
    width: 100%;
    text-align: left;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 20px 24px;
    background: none;
    border: none;
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
}

.faq-chevron {
    flex-shrink: 0;
    color: var(--text-tertiary);
    transition: transform var(--transition-fast);
}

.faq-item.open .faq-chevron {
    transform: rotate(180deg);
    color: var(--accent-1);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-med), padding var(--transition-med);
}

.faq-item.open .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding: 0 24px 20px;
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.7;
}

/* --- Footer --- */
.footer {
    border-top: 1px solid var(--border-subtle);
    padding: 64px 0 0;
}

.footer-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 32px;
}

.footer-top {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 48px;
    padding-bottom: 48px;
}

.footer-brand .nav-logo { margin-bottom: 16px; }

.footer-tagline {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.6;
    max-width: 300px;
}

.footer-links-group h4, .footer-links-group .footer-group-title {
    font-family: var(--font-display);
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 16px;
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.footer-links-group a {
    display: block;
    color: var(--text-secondary);
    font-size: 0.88rem;
    padding: 4px 0;
    transition: color var(--transition-fast);
}

.footer-languages-section {
    border-top: 1px solid var(--border-subtle);
    padding: 32px 0;
}

.footer-languages-section .footer-group-title {
    font-family: var(--font-display);
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 16px;
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.footer-lang-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
    gap: 10px 16px;
}

.lang-link {
    color: var(--text-secondary);
    font-size: 0.82rem;
    padding: 4px 8px;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
    text-decoration: none;
    display: inline-block;
}

.lang-link:hover {
    color: var(--accent-1);
    background: rgba(129, 140, 248, 0.08);
}

.lang-link.active {
    color: var(--accent-2);
    font-weight: 700;
    background: rgba(192, 132, 252, 0.12);
}

.footer-bottom {
    border-top: 1px solid var(--border-subtle);
    padding: 24px 0;
    text-align: center;
}

.footer-bottom p {
    color: var(--text-tertiary);
    font-size: 0.8rem;
}

/* --- Back to Top --- */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px; height: 48px;
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-1);
    cursor: pointer;
    z-index: 900;
    opacity: 0;
    visibility: hidden;
    transform: translateY(12px);
    transition: all var(--transition-fast);
    backdrop-filter: blur(12px);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: rgba(192, 132, 252, 0.1);
    border-color: var(--border-glow);
    transform: translateY(-2px);
}

/* --- Live Indicator --- */
.live-indicator {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--accent-1);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 12px;
}

.live-dot {
    width: 6px; height: 6px;
    background: var(--accent-1);
    border-radius: 50%;
    animation: pulse 1.5s ease-in-out infinite;
}

/* --- Responsive --- */
@media (max-width: 1024px) {
    .hero-container { grid-template-columns: 1fr; gap: 40px; text-align: center; }
    .hero-description { margin: 0 auto 36px; }
    .hero-actions { justify-content: center; }
    .hero-stats { justify-content: center; }
    .hero-visual { order: -1; }
    .hero-equation-container { width: 350px; height: 350px; }
    .calculator-layout { grid-template-columns: 1fr; }
    .features-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-top { grid-template-columns: 1fr 1fr; gap: 32px; }
    .proportion-grid { grid-template-columns: 1fr; }
    .proportion-connector { flex-direction: row; padding: 8px 20px; }
    .connector-line { width: 30px; height: 2px; }
}

@media (max-width: 768px) {
    :root { --section-gap: 80px; }

    .nav-links { display: none; }
    .nav-cta { display: none; }
    .mobile-menu-btn { display: flex; }

    .mobile-menu-btn.open span:nth-child(1) { transform: rotate(45deg) translateY(7px); }
    .mobile-menu-btn.open span:nth-child(2) { opacity: 0; }
    .mobile-menu-btn.open span:nth-child(3) { transform: rotate(-45deg) translateY(-7px); }

    .nav-links.open {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 100%; left: 0; right: 0;
        background: rgba(6, 6, 14, 0.95);
        backdrop-filter: blur(20px);
        padding: 16px 24px;
        border-bottom: 1px solid var(--border-subtle);
        gap: 4px;
    }

    .hero { min-height: auto; padding: 100px 0 60px; }
    .hero-title { font-size: 2.4rem; }
    .hero-equation-container { width: 280px; height: 280px; }

    .steps-grid { flex-direction: column; }
    .step-connector { transform: rotate(90deg); width: 40px; }

    .features-grid { grid-template-columns: 1fr; }
    .footer-top { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
    .hero-actions { flex-direction: column; align-items: stretch; }
    .hero-stats { flex-direction: column; gap: 16px; }
    .hero-stat-divider { width: 40px; height: 1px; }
    .result-extras { grid-template-columns: 1fr; }
}