/* ========================================
   Benkyo Marketing Website
   ======================================== */

:root {
    --red: #E85D5D;
    --red-dark: #c0392b;
    --indigo: #6c5ce7;
    --indigo-light: #a29bfe;
    --blue: #0984e3;
    --text: #1a1a2e;
    --text-secondary: #555;
    --text-muted: #888;
    --bg: #ffffff;
    --bg-alt: #f8f7f4;
    --bg-dark: #0f0f1a;
    --card: #ffffff;
    --border: #e8e8e8;
    --radius: 16px;
    --radius-sm: 10px;
    --radius-lg: 24px;
    --shadow: 0 2px 20px rgba(0,0,0,0.06);
    --shadow-lg: 0 8px 40px rgba(0,0,0,0.1);
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1120px;
    margin: 0 auto;
    padding: 0 24px;
}

img {
    max-width: 100%;
    height: auto;
}

a {
    color: inherit;
    text-decoration: none;
}

/* ========================================
   Navigation
   ======================================== */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(255,255,255,0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0,0,0,0.06);
    transition: var(--transition);
}

.nav.scrolled {
    box-shadow: 0 1px 10px rgba(0,0,0,0.08);
}

.nav-inner {
    max-width: 1120px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 1.1rem;
}

.nav-icon {
    width: 36px;
    height: 36px;
    border-radius: 8px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-links a {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color var(--transition);
}

.nav-links a:hover {
    color: var(--text);
}

.nav-links .btn {
    background: #FFD43B;
    color: #1a1a2e;
}

.nav-links .btn:hover {
    background: #FCC419;
    color: #1a1a2e;
}

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

.nav-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    transition: var(--transition);
}

.nav-mobile {
    display: none;
    flex-direction: column;
    padding: 12px 24px 20px;
    gap: 4px;
}

.nav-mobile a {
    padding: 10px 0;
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.nav-mobile .btn {
    margin-top: 8px;
    text-align: center;
}

/* ========================================
   Buttons
   ======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 22px;
    background: #000;
    color: white;
    border-radius: 100px;
    font-size: 0.9rem;
    font-weight: 600;
    transition: all var(--transition);
    border: none;
    cursor: pointer;
}

.btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(0,0,0,0.2);
}

.btn-sm {
    padding: 7px 16px;
    font-size: 0.82rem;
}

.btn-lg {
    padding: 14px 32px;
    font-size: 1rem;
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--border);
    color: var(--text);
}

.btn-outline:hover {
    border-color: var(--text);
    box-shadow: 0 4px 16px rgba(0,0,0,0.1);
}

.btn-pro {
    background: linear-gradient(135deg, var(--indigo-light), var(--indigo));
}

.btn-pro:hover {
    box-shadow: 0 4px 20px rgba(108, 92, 231, 0.4);
}

/* ========================================
   Hero
   ======================================== */
.hero {
    position: relative;
    padding: 140px 0 80px;
    overflow: hidden;
    min-height: 90vh;
    display: flex;
    align-items: center;
}

.hero-bg {
    position: absolute;
    inset: 0;
    overflow: hidden;
    z-index: 0;
}

.hero-circle {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.15;
}

.hero-circle-1 {
    width: 600px;
    height: 600px;
    background: var(--red);
    top: -200px;
    right: -100px;
}

.hero-circle-2 {
    width: 400px;
    height: 400px;
    background: var(--indigo);
    bottom: -100px;
    left: -100px;
}

.hero-circle-3 {
    width: 300px;
    height: 300px;
    background: #ffeaa7;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.hero-content {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-app-icon {
    margin-bottom: 20px;
    transition: transform var(--transition);
}

.hero-app-icon:hover {
    transform: scale(1.05);
}

.hero-kicker {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--red);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 16px;
}

.hero-heading {
    font-size: clamp(2.4rem, 5vw, 3.6rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 20px;
    letter-spacing: -0.02em;
}

.hero-gradient {
    background: linear-gradient(135deg, var(--red), var(--indigo));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-sub {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 32px;
    max-width: 480px;
}

.hero-actions {
    margin-bottom: 12px;
}

.hero-note {
    font-size: 0.82rem;
    color: var(--text-muted);
}

/* Phone Mockup */
.hero-visual {
    display: flex;
    justify-content: center;
    position: relative;
}

/* Floating badges */
.hero-float {
    position: absolute;
    display: flex;
    align-items: center;
    gap: 8px;
    background: white;
    padding: 8px 14px;
    border-radius: 100px;
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--text);
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    white-space: nowrap;
    z-index: 2;
    animation: floatBadge 3s ease-in-out infinite;
}

.hero-float svg {
    flex-shrink: 0;
    color: var(--red);
}

.hero-float-1 {
    top: 10%;
    right: -20px;
    animation-delay: 0s;
}

.hero-float-2 {
    bottom: 25%;
    left: -30px;
    animation-delay: 1s;
}

.hero-float-3 {
    top: 40%;
    right: -35px;
    animation-delay: 2s;
}

@keyframes floatBadge {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-8px); }
}

.phone-mockup {
    width: 280px;
    background: var(--text);
    border-radius: 36px;
    padding: 12px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.2), 0 0 0 1px rgba(255,255,255,0.1) inset;
    animation: phoneFloat 4s ease-in-out infinite;
}

@keyframes phoneFloat {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.phone-screen {
    background: var(--bg);
    border-radius: 26px;
    overflow: hidden;
    aspect-ratio: 9/17;
    display: flex;
    flex-direction: column;
}

/* Carousel */
.phone-carousel {
    flex: 1;
    position: relative;
    overflow: hidden;
}

.phone-slide {
    position: absolute;
    inset: 0;
    padding: 24px 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    opacity: 0;
    transform: translateX(30px);
    transition: opacity 0.5s ease, transform 0.5s ease;
    pointer-events: none;
}

.phone-slide.active {
    opacity: 1;
    transform: translateX(0);
    pointer-events: auto;
    position: relative;
}

.phone-slide.exit {
    opacity: 0;
    transform: translateX(-30px);
}

/* Dots */
.phone-dots {
    display: flex;
    justify-content: center;
    gap: 6px;
    padding: 10px 0 14px;
}

.phone-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    border: none;
    background: #ddd;
    cursor: pointer;
    transition: all var(--transition);
    padding: 0;
}

.phone-dot.active {
    background: var(--red);
    width: 18px;
    border-radius: 100px;
}

/* Shared demo styles */
.demo-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 4px;
}

.demo-label {
    font-weight: 700;
    font-size: 1.1rem;
}

.demo-badge {
    font-size: 0.7rem;
    font-weight: 600;
    background: var(--bg-alt);
    padding: 3px 9px;
    border-radius: 100px;
    color: var(--text-muted);
}

.demo-badge-indigo {
    background: #f0eeff;
    color: var(--indigo);
}

.demo-badge-blue {
    background: #e8f4fd;
    color: var(--blue);
}

.demo-badge-pink {
    background: #fde8f0;
    color: #e84393;
}

/* Screen 1: Library cards */
.demo-card {
    background: var(--bg-alt);
    border-radius: var(--radius-sm);
    padding: 14px;
    display: flex;
    flex-direction: column;
    gap: 3px;
}

.demo-kanji {
    font-family: 'Noto Sans JP', serif;
    font-size: 1.35rem;
    font-weight: 700;
}

.demo-reading {
    font-family: 'Noto Sans JP', sans-serif;
    font-size: 0.8rem;
    color: var(--red);
}

.demo-meaning {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* Screen 2: FlexSRS */
.demo-srs-card {
    background: linear-gradient(145deg, #2d1b69, #1a1145);
    border-radius: var(--radius-sm);
    padding: 20px;
    text-align: center;
    color: white;
}

.demo-srs-kanji {
    display: block;
    font-family: 'Noto Sans JP', serif;
    font-size: 2.8rem;
    font-weight: 700;
    line-height: 1.3;
}

.demo-srs-prompt {
    font-size: 0.7rem;
    opacity: 0.5;
}

.demo-srs-actions {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 6px;
}

.demo-srs-btn {
    display: block;
    padding: 8px;
    border-radius: 100px;
    font-size: 0.72rem;
    font-weight: 600;
    text-align: center;
}

.demo-srs-fail {
    background: rgba(232,93,93,0.12);
    color: #e17055;
}

.demo-srs-good {
    background: rgba(108,92,231,0.12);
    color: var(--indigo);
}

.demo-srs-easy {
    background: rgba(0,184,148,0.12);
    color: #00b894;
}

.demo-srs-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 6px;
    text-align: center;
}

.demo-srs-stats div {
    background: var(--bg-alt);
    border-radius: 8px;
    padding: 8px 4px;
}

.demo-srs-stats strong {
    display: block;
    font-size: 1rem;
}

.demo-srs-stats small {
    font-size: 0.6rem;
    color: var(--text-muted);
}

/* Screen 3: Quiz */
.demo-quiz-question {
    background: var(--bg-alt);
    border-radius: var(--radius-sm);
    padding: 20px;
    text-align: center;
}

.demo-quiz-kanji {
    display: block;
    font-family: 'Noto Sans JP', serif;
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.demo-quiz-hint {
    font-size: 0.72rem;
    color: var(--text-muted);
}

.demo-quiz-options {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.demo-quiz-opt {
    padding: 10px 14px;
    border-radius: 8px;
    font-size: 0.78rem;
    font-weight: 500;
    background: var(--bg-alt);
    border: 1.5px solid transparent;
    transition: all var(--transition);
}

.demo-quiz-correct {
    background: #e6f9f1;
    border-color: #00b894;
    color: #00b894;
    font-weight: 600;
}

/* Screen 4: Stats */
.demo-stats-streak {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 6px;
    text-align: center;
}

.demo-stats-streak div {
    background: var(--bg-alt);
    border-radius: 8px;
    padding: 8px 4px;
}

.demo-stats-streak span {
    font-size: 0.9rem;
}

.demo-stats-streak strong {
    display: block;
    font-size: 1.1rem;
}

.demo-stats-streak small {
    font-size: 0.6rem;
    color: var(--text-muted);
}

.demo-stats-bar {
    display: flex;
    height: 10px;
    border-radius: 100px;
    overflow: hidden;
    gap: 2px;
}

.demo-bar-fill {
    transition: width 1s ease;
}

.demo-stats-chart {
    display: flex;
    align-items: flex-end;
    gap: 4px;
    height: 60px;
    padding-top: 4px;
}

.demo-mini-bar {
    flex: 1;
    background: linear-gradient(to top, #74b9ff, #0984e3);
    border-radius: 3px 3px 0 0;
    min-height: 6px;
    opacity: 0.65;
}

.demo-mini-bar-last {
    background: linear-gradient(to top, #55efc4, #00b894);
    opacity: 1;
}

/* ========================================
   Stats
   ======================================== */
.stats {
    padding: 48px 0;
    background: var(--bg-alt);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 1.8rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    margin-bottom: 4px;
}

.stat-label {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-weight: 500;
}

/* ========================================
   Sections
   ======================================== */
.section-header {
    text-align: center;
    max-width: 600px;
    margin: 0 auto 56px;
}

.section-kicker {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--red);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 12px;
}

.section-header h2 {
    font-size: clamp(1.8rem, 3.5vw, 2.4rem);
    font-weight: 800;
    letter-spacing: -0.02em;
    margin-bottom: 16px;
}

.section-sub {
    font-size: 1.05rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ========================================
   Features Grid
   ======================================== */
.features {
    padding: 100px 0;
}

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

.feature-card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px;
    transition: all var(--transition);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: transparent;
}

.feature-icon {
    width: 52px;
    height: 52px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 8px;
}

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

/* ========================================
   Split Sections
   ======================================== */
.section-alt {
    padding: 100px 0;
    background: var(--bg-alt);
}

.split-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.split-reverse {
    direction: rtl;
}

.split-reverse > * {
    direction: ltr;
}

.split-text h2 {
    font-size: clamp(1.8rem, 3vw, 2.2rem);
    font-weight: 800;
    letter-spacing: -0.02em;
    margin-bottom: 16px;
}

.split-text > p {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 28px;
}

.check-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 14px;
}

.check-list li {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    font-size: 0.95rem;
    line-height: 1.5;
}

.check-list svg {
    flex-shrink: 0;
    color: #00b894;
    margin-top: 2px;
}

/* Card Stack Visual */
.card-stack {
    position: relative;
    width: 320px;
    height: 380px;
    margin: 0 auto;
}

.stack-card {
    position: absolute;
    width: 100%;
    background: white;
    border-radius: var(--radius);
    padding: 28px;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: 20px;
    transition: transform var(--transition);
    border: 1px solid var(--border);
}

.stack-card-1 {
    bottom: 0;
    z-index: 3;
}

.stack-card-2 {
    bottom: 80px;
    z-index: 2;
    transform: scale(0.96);
    opacity: 0.85;
}

.stack-card-3 {
    bottom: 150px;
    z-index: 1;
    transform: scale(0.92);
    opacity: 0.7;
}

.card-stack:hover .stack-card-1 {
    transform: translateY(-4px);
}

.card-stack:hover .stack-card-2 {
    transform: scale(0.96) translateY(-8px);
}

.card-stack:hover .stack-card-3 {
    transform: scale(0.92) translateY(-12px);
}

.stack-kanji {
    font-family: 'Noto Sans JP', serif;
    font-size: 2.8rem;
    font-weight: 700;
    line-height: 1;
}

.stack-info {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.stack-reading {
    font-family: 'Noto Sans JP', sans-serif;
    font-size: 0.95rem;
    color: var(--red);
    font-weight: 500;
}

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

.stack-jlpt {
    margin-left: auto;
    font-size: 0.75rem;
    font-weight: 700;
    background: var(--bg-alt);
    padding: 4px 10px;
    border-radius: 100px;
    color: var(--text-muted);
}

/* ========================================
   SRS Section
   ======================================== */
.section-srs {
    padding: 100px 0;
    background: var(--bg);
}

.srs-highlights {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.srs-highlight {
    display: flex;
    gap: 16px;
    align-items: flex-start;
}

.srs-icon {
    flex-shrink: 0;
    width: 44px;
    height: 44px;
    background: linear-gradient(135deg, #f0eeff, #e8e4ff);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--indigo);
}

.srs-highlight strong {
    display: block;
    font-size: 0.95rem;
    margin-bottom: 2px;
}

.srs-highlight p {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin: 0;
}

/* SRS Demo */
.srs-demo {
    background: linear-gradient(145deg, #2d1b69, #1a1145);
    border-radius: var(--radius-lg);
    padding: 32px;
    color: white;
    box-shadow: 0 20px 60px rgba(108, 92, 231, 0.3);
    max-width: 340px;
    margin: 0 auto;
}

.srs-demo-header {
    margin-bottom: 24px;
}

.srs-demo-title {
    display: block;
    font-size: 1.3rem;
    font-weight: 700;
}

.srs-demo-subtitle {
    font-size: 0.82rem;
    color: rgba(255,255,255,0.5);
}

.srs-demo-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    margin-bottom: 24px;
}

.srs-stat {
    text-align: center;
    background: rgba(255,255,255,0.08);
    border-radius: var(--radius-sm);
    padding: 12px 8px;
}

.srs-stat-num {
    display: block;
    font-size: 1.3rem;
    font-weight: 700;
}

.srs-stat-label {
    font-size: 0.7rem;
    color: rgba(255,255,255,0.5);
}

.srs-demo-card {
    background: rgba(255,255,255,0.06);
    border-radius: var(--radius-sm);
    padding: 24px;
    text-align: center;
    margin-bottom: 16px;
}

.srs-card-kanji {
    display: block;
    font-family: 'Noto Sans JP', serif;
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.srs-card-prompt {
    font-size: 0.82rem;
    color: rgba(255,255,255,0.5);
}

.srs-demo-actions {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
}

.srs-btn {
    padding: 10px;
    border: none;
    border-radius: 100px;
    font-size: 0.82rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition);
}

.srs-btn-fail {
    background: rgba(232,93,93,0.2);
    color: #ff7675;
}

.srs-btn-ok {
    background: rgba(108,92,231,0.3);
    color: #a29bfe;
}

.srs-btn-easy {
    background: rgba(0,184,148,0.2);
    color: #55efc4;
}

.srs-btn:hover {
    transform: translateY(-1px);
    filter: brightness(1.2);
}

/* ========================================
   Quiz Modes
   ======================================== */
.quiz-modes {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.quiz-mode {
    text-align: center;
    padding: 36px 24px;
    border-radius: var(--radius);
    background: white;
    border: 1px solid var(--border);
    transition: all var(--transition);
}

.quiz-mode:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: transparent;
}

.quiz-mode-icon {
    width: 64px;
    height: 64px;
    border-radius: 16px;
    background: var(--bg-alt);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    color: var(--blue);
    transition: all var(--transition);
}

.quiz-mode:hover .quiz-mode-icon {
    background: linear-gradient(135deg, #74b9ff, #0984e3);
    color: white;
}

.quiz-mode h3 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.quiz-mode p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* ========================================
   Statistics Section
   ======================================== */
.section-stats {
    padding: 100px 0;
    background: var(--bg);
}

.stats-features-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.stats-feature-item {
    display: flex;
    gap: 16px;
    align-items: flex-start;
}

.stats-feature-icon {
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, #ffe0e6, #ffd0d8);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--red);
}

.stats-feature-item strong {
    display: block;
    font-size: 0.95rem;
    margin-bottom: 2px;
}

.stats-feature-item p {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin: 0;
}

/* Stats Dashboard Mockup */
.stats-dashboard {
    background: white;
    border-radius: var(--radius-lg);
    padding: 28px;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border);
    max-width: 380px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

/* Streak Row */
.sd-streak-row {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    text-align: center;
}

.sd-streak-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
}

.sd-streak-icon {
    font-size: 1.2rem;
}

.sd-streak-num {
    font-size: 1.5rem;
    font-weight: 800;
    line-height: 1.2;
}

.sd-streak-label {
    font-size: 0.7rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    font-weight: 600;
}

/* Week View */
.sd-week {
    display: flex;
    justify-content: space-between;
    gap: 6px;
}

.sd-day {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    padding: 8px 4px;
    border-radius: var(--radius-sm);
    background: var(--bg-alt);
}

.sd-day span {
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--text-muted);
}

.sd-day-done {
    background: #e6f9f1;
    color: #00b894;
}

.sd-day-done svg {
    color: #00b894;
}

.sd-day-miss {
    background: var(--bg-alt);
}

.sd-day-miss::after {
    content: '';
    width: 14px;
    height: 14px;
    border-radius: 50%;
    border: 2px dashed #ddd;
}

.sd-day-today {
    background: #fff3e0;
    border: 2px solid #fdcb6e;
}

.sd-day-today::after {
    content: '';
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: #fdcb6e;
}

/* Mastery Bar */
.sd-mastery {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.sd-mastery-label {
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--text);
}

.sd-mastery-bar {
    display: flex;
    height: 14px;
    border-radius: 100px;
    overflow: hidden;
    gap: 2px;
}

.sd-bar-seg {
    transition: width 1s ease;
}

.sd-bar-mastered { background: #0984e3; }
.sd-bar-good { background: #00b894; }
.sd-bar-confirm { background: #fdcb6e; }
.sd-bar-bad { background: #e17055; }
.sd-bar-new { background: #b2bec3; }

.sd-mastery-legend {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.sd-mastery-legend span {
    display: flex;
    align-items: center;
    gap: 4px;
    font-size: 0.68rem;
    color: var(--text-muted);
    font-weight: 500;
}

.sd-mastery-legend i {
    display: inline-block;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    font-style: normal;
}

/* Mini Chart */
.sd-chart {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.sd-chart-label {
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--text);
}

.sd-chart-bars {
    display: flex;
    align-items: flex-end;
    gap: 4px;
    height: 80px;
    padding: 4px 0;
}

.sd-chart-bar {
    flex: 1;
    background: linear-gradient(to top, #74b9ff, #0984e3);
    border-radius: 4px 4px 0 0;
    min-height: 8px;
    transition: height 0.6s ease;
    opacity: 0.7;
}

.sd-chart-bar:hover {
    opacity: 1;
}

.sd-chart-bar-latest {
    background: linear-gradient(to top, #55efc4, #00b894);
    opacity: 1;
}

.sd-chart-avg {
    text-align: right;
}

.sd-chart-avg span {
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--text-muted);
    background: var(--bg-alt);
    padding: 2px 8px;
    border-radius: 100px;
}

@media (max-width: 768px) {
    .stats-dashboard {
        max-width: 100%;
    }
}

/* ========================================
   JLPT Section
   ======================================== */
.section-jlpt {
    padding: 80px 0;
    background: linear-gradient(170deg, #fdf6ec 0%, #fff1e0 50%, #fdf6ec 100%);
    border-top: 1px solid #f0e4d0;
    border-bottom: 1px solid #f0e4d0;
    position: relative;
    overflow: hidden;
}

.section-jlpt::before {
    content: '日本語能力試験';
    position: absolute;
    font-family: 'Noto Sans JP', serif;
    font-size: clamp(4rem, 10vw, 8rem);
    font-weight: 700;
    color: rgba(0,0,0,0.03);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    white-space: nowrap;
    pointer-events: none;
    letter-spacing: 0.05em;
}

.section-jlpt .section-kicker {
    color: #c0392b;
}

.jlpt-levels {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

.jlpt-level {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.jlpt-badge {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    font-size: 1.1rem;
    color: white;
    transition: transform var(--transition);
}

.jlpt-badge:hover {
    transform: scale(1.1);
}

.jlpt-n5 { background: linear-gradient(135deg, #55efc4, #00b894); }
.jlpt-n4 { background: linear-gradient(135deg, #74b9ff, #0984e3); }
.jlpt-n3 { background: linear-gradient(135deg, #ffeaa7, #fdcb6e); color: #2d3436; }
.jlpt-n2 { background: linear-gradient(135deg, #fd79a8, #e84393); }
.jlpt-n1 { background: linear-gradient(135deg, #a29bfe, #6c5ce7); }

.jlpt-desc {
    font-size: 0.78rem;
    color: var(--text-muted);
    font-weight: 500;
}

.jlpt-arrow {
    color: #d4c4a8;
}

/* ========================================
   Pro Section
   ======================================== */
.section-pro {
    padding: 100px 0;
    background: var(--bg-dark);
}

.pro-card {
    background: linear-gradient(145deg, rgba(108,92,231,0.15), rgba(162,155,254,0.05));
    border: 1px solid rgba(108,92,231,0.2);
    border-radius: var(--radius-lg);
    padding: 60px;
    text-align: center;
    color: white;
}

.pro-crown {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 64px;
    height: 64px;
    border-radius: 50%;
    background: linear-gradient(135deg, #ffeaa7, #fdcb6e);
    color: #2d3436;
    margin-bottom: 20px;
}

.pro-card h2 {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 8px;
}

.pro-sub {
    color: rgba(255,255,255,0.6);
    font-size: 1.05rem;
    margin-bottom: 48px;
}

.pro-features {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
    text-align: left;
    margin-bottom: 48px;
}

.pro-col h4 {
    font-size: 0.9rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--indigo-light);
}

.pro-col ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.pro-col li {
    font-size: 0.88rem;
    color: rgba(255,255,255,0.7);
    padding-left: 20px;
    position: relative;
}

.pro-col li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 8px;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--indigo-light);
}

.pro-cta {
    margin-top: 8px;
}

.pro-note {
    font-size: 0.82rem;
    color: rgba(255,255,255,0.4);
    margin-top: 12px;
}

/* ========================================
   Also Available (Kana)
   ======================================== */
.section-also {
    padding: 80px 0;
    background: var(--bg-alt);
}

.also-content {
    display: flex;
    align-items: center;
    gap: 48px;
    max-width: 720px;
    margin: 0 auto;
}

.also-icon {
    width: 140px;
    height: 140px;
    border-radius: 28px;
    flex-shrink: 0;
    box-shadow: var(--shadow-lg);
}

.also-text {
    text-align: left;
}

.also-text h2 {
    font-size: clamp(1.4rem, 2.5vw, 1.8rem);
    font-weight: 800;
    letter-spacing: -0.02em;
    margin-bottom: 12px;
}

.also-text p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 20px;
}

@media (max-width: 600px) {
    .also-content {
        flex-direction: column;
        text-align: center;
    }

    .also-text {
        text-align: center;
    }

    .also-icon {
        width: 100px;
        height: 100px;
        border-radius: 22px;
    }
}

/* ========================================
   FAQ Section
   ======================================== */
.section-faq {
    padding: 100px 0;
    background: var(--bg);
}

.faq-list {
    max-width: 720px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

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

.faq-item[open] {
    box-shadow: var(--shadow);
    border-color: transparent;
}

.faq-question {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 24px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    list-style: none;
    user-select: none;
    transition: color var(--transition);
}

.faq-question::-webkit-details-marker {
    display: none;
}

.faq-question::after {
    content: '+';
    font-size: 1.3rem;
    font-weight: 400;
    color: var(--text-muted);
    transition: transform var(--transition);
    flex-shrink: 0;
    margin-left: 16px;
}

.faq-item[open] .faq-question::after {
    content: '−';
}

.faq-question:hover {
    color: var(--red);
}

.faq-answer {
    padding: 0 24px 20px;
}

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

/* ========================================
   CTA Section
   ======================================== */
.section-cta {
    padding: 100px 0;
    background: linear-gradient(135deg, var(--red), #c0392b);
    text-align: center;
    color: white;
}

.cta-content h2 {
    font-size: clamp(1.8rem, 3.5vw, 2.4rem);
    font-weight: 800;
    margin-bottom: 12px;
}

.cta-content p {
    font-size: 1.05rem;
    opacity: 0.85;
    margin-bottom: 48px;
}

.section-cta .btn {
    background: white;
    color: var(--red);
}

.section-cta .btn:hover {
    box-shadow: 0 4px 20px rgba(0,0,0,0.2);
}

/* CTA Download Layout */
.cta-download {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 48px;
}

.cta-left {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.cta-app-icon {
    flex-shrink: 0;
    transition: transform var(--transition);
}

.cta-app-icon:hover {
    transform: scale(1.05);
}

/* Vertical Divider (desktop only) */
.cta-divider {
    display: none;
    width: 1px;
    height: 210px;
    background: rgba(255, 255, 255, 0.25);
    flex-shrink: 0;
}

/* QR Code (desktop only) */
.cta-qr {
    display: none;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

.cta-qr-img {
    width: 190px;
    height: 190px;
    border-radius: var(--radius);
}

.cta-qr-label {
    font-size: 0.82rem;
    opacity: 0.7;
    font-weight: 500;
}

/* Show divider and QR code only on desktop (non-touch devices with wide screens) */
@media (min-width: 769px) and (hover: hover) {
    .cta-divider {
        display: block;
    }

    .cta-qr {
        display: flex;
    }
}

/* ========================================
   Footer
   ======================================== */
.footer {
    padding: 40px 0;
    background: var(--bg-alt);
    border-top: 1px solid var(--border);
}

.footer-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 20px;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 12px;
}

.footer-icon {
    width: 40px;
    height: 40px;
    border-radius: 10px;
}

.footer-brand strong {
    display: block;
    font-size: 0.95rem;
}

.footer-brand span {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.footer-links {
    display: flex;
    gap: 24px;
}

.footer-links a {
    font-size: 0.85rem;
    color: var(--text-muted);
    transition: color var(--transition);
}

.footer-links a:hover {
    color: var(--text);
}

.footer-copy {
    font-size: 0.8rem;
    color: var(--text-muted);
}

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

.fade-in {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ========================================
   Responsive
   ======================================== */
@media (max-width: 1024px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .quiz-modes {
        grid-template-columns: repeat(2, 1fr);
    }

    .pro-features {
        grid-template-columns: 1fr;
        gap: 32px;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .nav-toggle {
        display: flex;
    }

    .nav-mobile.open {
        display: flex;
    }

    .hero {
        padding: 120px 0 60px;
        min-height: auto;
    }

    .hero-content {
        grid-template-columns: 1fr;
        gap: 48px;
        text-align: center;
    }

    .hero-sub {
        margin-left: auto;
        margin-right: auto;
    }

    .hero-visual {
        order: -1;
    }

    .phone-mockup {
        width: 240px;
        animation: none;
    }

    .hero-float {
        display: none;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }

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

    .split-section {
        grid-template-columns: 1fr;
        gap: 48px;
    }

    .split-reverse {
        direction: ltr;
    }

    .card-stack {
        width: 280px;
        height: 340px;
    }

    .quiz-modes {
        grid-template-columns: 1fr;
    }

    .jlpt-arrow {
        display: none;
    }

    .jlpt-levels {
        gap: 12px;
    }

    .pro-card {
        padding: 36px 24px;
    }

    .cta-download {
        flex-direction: column;
        gap: 24px;
    }

    .footer-inner {
        flex-direction: column;
        text-align: center;
    }

    .footer-links {
        flex-wrap: wrap;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .hero-heading {
        font-size: 2rem;
    }

    .stat-number {
        font-size: 1.4rem;
    }

    .jlpt-badge {
        width: 52px;
        height: 52px;
        font-size: 0.95rem;
    }
}