/* 
 * Kikupass Design System v2.0 (Light Theme)
 * Professional, clean, and high-quality UI for driving license study.
 */

@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@400;500;600;700;800;900&family=Noto+Sans+JP:wght@400;500;700;900&display=swap');

:root {
    /* Primary Palette */
    --primary-blue: #2563eb;
    --primary-blue-soft: #dbeafe;
    --primary-blue-glow: rgba(37, 99, 235, 0.2);
    
    --success-green: #10b981;
    --success-green-soft: #d1fae5;
    
    --accent-purple: #6366f1;
    --accent-purple-soft: #e0e7ff;
    
    --danger-red: #ef4444;
    --danger-red-soft: #fee2e2;

    /* Neutrals */
    --bg-main: #f8fafc;
    --bg-card: #ffffff;
    --text-main: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --border-light: #e2e8f0;
    
    /* Effects */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --border-radius-lg: 24px;
    --border-radius-md: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: 'Outfit', 'Noto Sans JP', sans-serif;
    background-color: var(--bg-main);
    color: var(--text-main);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
}

#app-container {
    max-width: 640px;
    margin: 0 auto;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    padding: 0 16px;
}

@media (min-width: 1024px) {
    #app-container {
        max-width: 1200px;
        padding: 0 40px;
    }
}

/* Header & Navigation */
.site-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 24px 0;
}

.header-right-group {
    display: flex;
    align-items: center;
    gap: 12px;
}

.header-sns-share {
    display: flex;
    align-items: center;
    gap: 8px;
    background: white;
    padding: 6px 12px;
    border-radius: 100px;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-sm);
}

.sns-share-label {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--text-secondary);
    white-space: nowrap;
    display: flex;
    align-items: center;
    gap: 4px;
}

.sns-share-label i {
    color: var(--danger-red);
}

.sns-icon-group {
    display: flex;
    align-items: center;
    gap: 6px;
}

.logo-group {
    display: flex;
    flex-direction: column;
}

.logo-group h1 {
    font-size: 1.5rem;
    font-weight: 900;
    letter-spacing: -0.02em;
    color: var(--primary-blue);
    line-height: 1;
}

.logo-group h1 span {
    color: var(--text-main);
}

.logo-group .tagline {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-top: 4px;
}

.header-nav .nav-link {
    font-size: 0.875rem;
    font-weight: 700;
    color: var(--text-secondary);
    text-decoration: none;
    padding: 8px 16px;
    background: white;
    border-radius: 100px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
    transition: var(--transition);
}

.header-nav .nav-link:hover {
    color: var(--primary-blue);
    border-color: var(--primary-blue);
    transform: translateY(-1px);
}

/* Hero Section */
.hero {
    padding: 40px 0 24px;
    text-align: center;
}

.catchphrase-container {
    display: grid;
    place-items: center;
    margin-bottom: 12px;
    min-height: 3rem;
}

.catchphrase {
    grid-area: 1 / 1 / 2 / 2;
    font-size: 2.25rem;
    font-weight: 900;
    line-height: 1.2;
    letter-spacing: -0.04em;
    margin-bottom: 0;
    opacity: 0;
    visibility: hidden;
    transition: opacity 1.5s ease-in-out, visibility 1.5s;
    width: 100%;
}

.catchphrase.active {
    opacity: 1;
    visibility: visible;
}

@media (max-width: 480px) {
    .catchphrase {
        font-size: 1.75rem;
    }
}

.catchphrase .accent {
    color: var(--primary-blue);
}

.hero .description {
    font-size: 1rem;
    color: var(--text-secondary);
    max-width: 480px;
    margin: 0 auto;
}

/* Views */
.view {
    flex: 1;
    display: flex;
    flex-direction: column;
    animation: fadeIn 0.4s ease-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

.hidden {
    display: none !important;
}

/* Home Cards */
.card {
    background: var(--bg-card);
    border-radius: var(--border-radius-lg);
    padding: 24px;
    margin-bottom: 24px;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-light);
}

.card-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 20px;
}

.card-header i {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    font-size: 1rem;
}

.card-header h3 {
    font-size: 1.125rem;
    font-weight: 800;
}

.card-footer-action {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid var(--border-light);
}

/* Mode Specific Icons/Colors */
.icon-exercise { background: var(--primary-blue-soft); color: var(--primary-blue); }
.icon-listen { background: var(--success-green-soft); color: var(--success-green); }
.icon-settings { background: #f1f5f9; color: var(--text-secondary); }

/* Grid Layout */
.grid-2col {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}

@media (max-width: 480px) {
    .grid-2col {
        grid-template-columns: 1fr;
    }
}

.grid-4col {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
}

@media (max-width: 768px) {
    .grid-4col {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .grid-4col {
        grid-template-columns: 1fr;
    }
}

.grid-3col {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
}

@media (max-width: 768px) {
    .grid-3col {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .grid-3col {
        grid-template-columns: 1fr;
    }
}

/* Buttons */
.btn-mode {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 16px 8px;
    border-radius: var(--border-radius-md);
    border: 2px solid transparent;
    font-weight: 700;
    font-size: 0.85rem;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
    background: #f8fafc;
    color: var(--text-secondary);
    min-height: 80px;
}

.btn-mode:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-exercise { color: var(--primary-blue); border-color: var(--primary-blue-soft); }
.btn-exercise:hover { background: var(--primary-blue); color: white; border-color: var(--primary-blue); }

.btn-listen { color: var(--success-green); border-color: var(--success-green-soft); }
.btn-listen:hover { background: var(--success-green); color: white; border-color: var(--success-green); }

.btn-cat { color: var(--accent-purple); border-color: var(--accent-purple-soft); }
.btn-cat:hover { background: var(--accent-purple); color: white; border-color: var(--accent-purple); }

/* Settings Form */
.settings-list {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.setting-row {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.setting-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.setting-info label {
    font-size: 0.9375rem;
    font-weight: 700;
}

.badge-value {
    background: #f1f5f9;
    padding: 4px 10px;
    border-radius: 6px;
    font-weight: 800;
    font-size: 0.8125rem;
    color: var(--primary-blue);
}

/* Range Input Refinement */
input[type="range"] {
    -webkit-appearance: none;
    height: 8px;
    background: #e2e8f0;
    border-radius: 4px;
    cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 24px;
    height: 24px;
    background: white;
    border: 2px solid var(--primary-blue);
    border-radius: 50%;
    box-shadow: var(--shadow-sm);
}

/* Toggle Switch (iOS Style) */
.switch {
    position: relative;
    display: inline-block;
    width: 50px;
    height: 28px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #cbd5e1;
    transition: .4s;
    border-radius: 34px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 22px;
    width: 22px;
    left: 3px;
    bottom: 3px;
    background-color: white;
    transition: .4s;
    border-radius: 50%;
    box-shadow: var(--shadow-sm);
}

input:checked + .slider {
    background-color: var(--primary-blue);
}

input:checked + .slider:before {
    transform: translateX(22px);
}

.setting-row.horizontal {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
}

/* Footer */
.site-footer {
    padding: 48px 0;
    text-align: center;
}

.footer-nav {
    display: flex;
    justify-content: center;
    gap: 24px;
    margin-bottom: 24px;
}

.footer-nav a {
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 600;
    transition: var(--transition);
}

.footer-nav a:hover {
    color: var(--primary-blue);
}

.copyright {
    color: var(--text-muted);
    font-size: 0.75rem;
    font-weight: 500;
}

/* --- Exercise View Styles --- */
.exercise-main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.view-header-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 0;
    margin-bottom: 16px;
}

.btn-ghost {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.25rem;
    cursor: pointer;
    padding: 8px;
    border-radius: 50%;
    transition: var(--transition);
}

.btn-ghost:hover {
    background: rgba(0,0,0,0.05);
}

.progress-bar {
    flex: 1;
    height: 10px;
    background: #e2e8f0;
    border-radius: 100px;
    margin: 0 20px;
    overflow: hidden;
}

#progress-fill {
    height: 100%;
    width: 0%;
    background: var(--primary-blue);
    border-radius: 100px;
    transition: width 0.3s ease;
}

.question-card {
    background: white;
    border-radius: var(--border-radius-lg);
    padding: 40px 24px;
    text-align: center;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-light);
    margin-bottom: 24px;
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    position: relative;
}

#visualizer-bars {
    display: flex;
    justify-content: center;
    gap: 8px;
    height: 40px;
    margin-bottom: 24px;
}

.bar {
    width: 4px;
    height: 12px;
    background: var(--primary-blue);
    border-radius: 100px;
    transition: var(--transition);
    opacity: 0.3;
}

.active .bar {
    animation: wave 1.2s infinite ease-in-out;
}

@keyframes wave {
    0%, 100% { transform: scaleY(1); opacity: 0.2; }
    50% { transform: scaleY(2.5); opacity: 0.8; }
}

#question-text {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-main);
    line-height: 1.6;
    padding: 0 16px;
}

/* Feedback Overlay within Card */
#feedback-area {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.feedback-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
}

#user-result-text {
    font-size: 1.5rem;
    font-weight: 900;
}

.text-correct { color: var(--primary-blue); }
.text-wrong { color: var(--danger-red); }

.answer-symbol {
    font-size: 8rem;
    font-weight: 900;
    line-height: 1;
    margin: 8px 0;
}

.answer-symbol.correct { color: var(--primary-blue); }
.answer-symbol.wrong { color: var(--danger-red); }

#result-explanation {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-secondary);
    padding: 20px;
    background: #f8fafc;
    border-radius: 16px;
    width: 100%;
    margin-top: 16px;
    text-align: left;
    border: 1px solid var(--border-light);
}

/* Control Buttons */
.controls {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 32px;
}

.btn-answer {
    height: 140px;
    border-radius: var(--border-radius-lg);
    border: none;
    font-size: 4rem;
    font-weight: 900;
    cursor: pointer;
    transition: var(--transition);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-answer:active {
    transform: scale(0.95);
    filter: brightness(0.9);
}

.btn-maru { background: var(--primary-blue); box-shadow: 0 12px 24px var(--primary-blue-glow); }
.btn-batsu { background: var(--danger-red); box-shadow: 0 12px 24px var(--danger-red-soft); }

.btn-next {
    background: var(--text-main);
    color: white;
    padding: 16px;
    border-radius: 16px;
    font-weight: 800;
    font-size: 1.125rem;
    border: none;
    width: 100%;
    cursor: pointer;
    margin-top: 24px;
}

/* Modal Styling */
.modal {
    position: fixed;
    inset: 0;
    background: rgba(15, 23, 42, 0.6);
    backdrop-filter: blur(8px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
    z-index: 1000;
}

.modal-card {
    background: white;
    border-radius: 32px;
    padding: 32px;
    width: 100%;
    max-width: 400px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    text-align: center;
}

.modal-card h2 {
    font-size: 1.5rem;
    font-weight: 900;
    margin-bottom: 8px;
}

.modal-card p {
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.input-count {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-bottom: 32px;
}

.input-count input {
    width: 80px;
    height: 60px;
    text-align: center;
    font-size: 1.5rem;
    font-weight: 900;
    border: 2px solid var(--border-light);
    border-radius: 16px;
    background: #f8fafc;
}

.modal-actions {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}

.btn-action {
    padding: 14px;
    border-radius: 12px;
    font-weight: 700;
    border: none;
    cursor: pointer;
}

.btn-start { background: var(--primary-blue); color: white; }
.btn-cancel { background: #f1f5f9; color: var(--text-secondary); }

/* Category List */
.category-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 12px;
    padding-bottom: 40px;
}

@media (min-width: 640px) {
    .category-grid { grid-template-columns: 1fr 1fr; }
}

.cat-item {
    background: white;
    padding: 16px 20px;
    border-radius: 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border: 1px solid var(--border-light);
    cursor: pointer;
    transition: var(--transition);
}

.cat-item:hover {
    border-color: var(--primary-blue);
    background: var(--primary-blue-soft);
}

.cat-label {
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 700;
}

.cat-num {
    color: var(--primary-blue);
    font-weight: 900;
    font-size: 0.875rem;
}

/* History Sidebar & Layout */
#view-exercise {
    display: flex;
    flex-direction: column;
    min-height: 100%;
}

.sidebar-overlay {
    position: fixed;
    inset: 0;
    background: rgba(15, 23, 42, 0.4);
    backdrop-filter: blur(4px);
    z-index: 1050;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}

.sidebar-overlay.open {
    opacity: 1;
    visibility: visible;
}

#sidebar-history {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: 280px;
    background: rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    z-index: 1100;
    padding: 20px;
    border-right: 1px solid var(--border-light);
    transform: translateX(-100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    flex-direction: column;
}

#sidebar-history.open {
    transform: translateX(0);
    box-shadow: var(--shadow-lg);
}

.header-left-group {
    display: flex;
    gap: 8px;
}

/* Sidebar Handle */
.sidebar-handle {
    position: fixed;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 24px;
    height: 60px;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(8px);
    border: 1px solid var(--border-light);
    border-left: none;
    border-radius: 0 12px 12px 0;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    z-index: 1200;
    color: var(--primary-blue);
    box-shadow: 2px 0 8px rgba(0,0,0,0.05);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), background 0.3s, width 0.3s;
}

.sidebar-handle:hover {
    width: 30px;
    background: white;
}

#view-exercise.sidebar-open .sidebar-handle {
    transform: translate(280px, -50%);
}

#view-exercise.sidebar-open .sidebar-handle i {
    transform: rotate(180deg);
}


@media (min-width: 1024px) {
    #view-exercise {
        flex-direction: row;
        gap: 32px;
        padding-left: 20px; /* Space from edge */
    }
    
    #sidebar-history {
        position: static;
        transform: none !important;
        width: 280px;
        flex-direction: column;
        background: white !important; /* Solid on desktop */
        backdrop-filter: none !important;
        border-radius: 24px;
        padding: 20px;
        border: 1px solid var(--border-light);
        z-index: auto;
        box-shadow: none !important;
    }
    
    #sidebar-overlay, .sidebar-handle {
        display: none !important;
    }
    
    .exercise-main-content {
        flex: 1;
    }
}

.history-list {
    margin-top: 16px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    max-height: 400px;
    overflow-y: auto;
    overflow-x: visible; /* Prevent horizontal clipping */
    padding: 4px; /* Space for shadows/outlines */
}

.history-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 16px;
    border-radius: 10px;
    font-weight: 700;
    font-size: 0.875rem;
    position: relative;
    cursor: pointer;
}

/* Global Tooltip Styling */
.tooltip {
    position: fixed;
    background: rgba(15, 23, 42, 0.95);
    color: white;
    padding: 12px 18px;
    border-radius: 12px;
    font-size: 0.875rem;
    font-weight: 500;
    width: auto;
    max-width: 300px;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3);
    z-index: 9999;
    pointer-events: none;
    transition: opacity 0.2s ease;
    text-align: left;
    line-height: 1.5;
    transform: translate(-50%, -100%); /* Position above the point */
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.tooltip::after {
    content: '';
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    border: 8px solid transparent;
    border-top-color: rgba(15, 23, 42, 0.95);
}

.history-item.correct { background: var(--primary-blue-soft); color: var(--primary-blue); }
.history-item.wrong { background: var(--danger-red-soft); color: var(--danger-red); }

.stats-footer {
    text-align: center;
    color: var(--text-muted);
    font-weight: 700;
    margin-top: 16px;
    padding-top: 16px;
    border-top: 1px solid var(--border-light);
}

#score {
    font-size: 1rem;
    color: var(--primary-blue);
    background: var(--primary-blue-soft);
    padding: 6px 12px;
    border-radius: 8px;
}

/* Ad Placeholder */
.ad-placeholder {
    background: #f1f5f9;
    padding: 12px;
    text-align: center;
    border-radius: 12px;
    color: var(--text-muted);
    font-size: 0.75rem;
    font-weight: 700;
    margin-top: auto;
}

/* Legal Pages Specific */
.legal-container {
    padding: 40px 0;
}

.legal-card {
    background: white;
    border-radius: 24px;
    padding: 40px;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-light);
}

.legal-card h1 {
    font-size: 1.75rem;
    font-weight: 900;
    margin-bottom: 24px;
    color: var(--primary-blue);
}

.legal-card h2 {
    font-size: 1.25rem;
    font-weight: 800;
    margin-top: 32px;
    margin-bottom: 12px;
}

.legal-card p, .legal-card ul {
    color: var(--text-secondary);
    margin-bottom: 16px;
    line-height: 1.8;
}

.legal-card ul {
    padding-left: 24px;
}

/* Results View */
.result-card {
    text-align: center;
    padding: 48px 32px;
}

.result-score-container {
    margin-bottom: 16px;
}

#result-score-big {
    font-size: 5rem;
    font-weight: 900;
    color: var(--primary-blue);
    line-height: 1;
}

.result-total {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-muted);
}

#result-message {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.result-stats {
    display: flex;
    justify-content: center;
    gap: 24px;
    margin-bottom: 40px;
}

.stat-box {
    background: #f8fafc;
    padding: 16px 24px;
    border-radius: 16px;
    border: 1px solid var(--border-light);
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.stat-label {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--text-muted);
    text-transform: uppercase;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 900;
    color: var(--text-main);
}

/* ===== SEO Sections (index.html 下部) ===== */
.seo-section {
    margin-bottom: 20px;
}

.seo-content {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    line-height: 1.8;
}

.seo-content p {
    margin-bottom: 16px;
}

/* サービス概要 特徴リスト */
.seo-feature-list {
    list-style: none;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.seo-feature-list li {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    background: #f8fafc;
    padding: 16px;
    border-radius: 12px;
    border: 1px solid var(--border-light);
}

.seo-icon {
    flex-shrink: 0;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-card);
    border-radius: 10px;
    color: var(--primary-blue);
    font-size: 1rem;
}

/* ターゲットリスト */
.seo-target-list {
    list-style: none;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.seo-target-list li {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 18px 20px;
    background: #f8fafc;
    border-radius: 14px;
    border: 1px solid var(--border-light);
    font-size: 0.9375rem;
    line-height: 1.6;
    text-align: center;
    justify-content: center;
}

.seo-target-list li i {
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-blue);
    font-size: 1.1rem;
}

/* 3ステップガイド */
.seo-steps {
    list-style: none;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 16px;
    counter-reset: step-counter;
}

.seo-steps li {
    display: flex;
    gap: 16px;
    align-items: flex-start;
    background: #f8fafc;
    padding: 16px;
    border-radius: 12px;
    border: 1px solid var(--border-light);
}

.step-number {
    flex-shrink: 0;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-blue);
    color: white;
    font-weight: 900;
    font-size: 1rem;
    border-radius: 50%;
}

/* FAQ */
.seo-faq {
    display: flex;
    flex-direction: column;
    gap: 0;
}

.seo-faq dt {
    font-weight: 800;
    color: var(--text-main);
    padding: 16px 16px 8px;
    cursor: pointer;
    border-bottom: none;
    position: relative;
}

.seo-faq dt::before {
    content: "Q. ";
    color: var(--primary-blue);
    font-weight: 900;
}

.seo-faq dd {
    color: var(--text-secondary);
    padding: 0 16px 16px;
    margin: 0;
    border-bottom: 1px solid var(--border-light);
    line-height: 1.8;
}

.seo-faq dd:last-of-type {
    border-bottom: none;
}

/* ===== Column Page Styles ===== */
.column-breadcrumb {
    font-size: 0.8125rem;
    color: var(--text-muted);
    margin-bottom: 16px;
}

.column-breadcrumb a {
    color: var(--text-muted);
    text-decoration: none;
}

.column-breadcrumb a:hover {
    color: var(--primary-blue);
}

.column-lead {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text-main);
    background: var(--primary-blue-soft);
    padding: 20px;
    border-radius: 14px;
    margin-bottom: 28px;
    line-height: 1.7;
}

.column-toc {
    background: #f8fafc;
    border: 1px solid var(--border-light);
    border-radius: 14px;
    padding: 20px 24px;
    margin-bottom: 32px;
}

.column-toc .toc-title {
    font-weight: 800;
    font-size: 1rem;
    margin-bottom: 12px;
    color: var(--text-main);
}

.column-toc ol {
    padding-left: 20px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.column-toc ol li a {
    color: var(--primary-blue);
    text-decoration: none;
    font-size: 0.9375rem;
    font-weight: 600;
}

.column-toc ol li a:hover {
    text-decoration: underline;
}

/* エピソードボックス */
.column-episode {
    background: #fffbeb;
    border: 1px solid #fde68a;
    border-radius: 14px;
    padding: 20px;
    margin: 20px 0;
}

/* 注意喚起 */
.column-warning {
    background: #fef2f2;
    border: 1px solid #fecaca;
    border-radius: 12px;
    padding: 14px 18px;
    margin: 16px 0;
    font-size: 0.875rem;
    color: #991b1b;
    line-height: 1.7;
}

.column-warning i {
    color: #dc2626;
    margin-right: 6px;
}

.episode-label {
    font-weight: 800;
    font-size: 0.875rem;
    color: #d97706;
    margin-bottom: 12px;
}

.episode-label i {
    margin-right: 6px;
}

.column-episode p {
    margin-bottom: 10px;
    font-size: 0.9375rem;
    line-height: 1.8;
}

.column-episode p:last-child {
    margin-bottom: 0;
}

/* フィーチャーボックス */
.column-feature-box {
    background: #f8fafc;
    border: 1px solid var(--border-light);
    border-radius: 14px;
    padding: 20px;
    margin: 12px 0;
}

.column-feature-box h4 {
    font-size: 1rem;
    font-weight: 800;
    margin-bottom: 8px;
}

.column-feature-box p {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    margin-bottom: 0;
}

/* 学習サイクルリスト */
.column-cycle {
    list-style: none;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin: 16px 0;
}

.column-cycle li {
    padding: 14px 18px;
    background: #f8fafc;
    border-radius: 12px;
    border: 1px solid var(--border-light);
    font-size: 0.9375rem;
    line-height: 1.7;
}

.column-cycle li strong {
    color: var(--primary-blue);
}

/* desktop 2カラム */
@media (min-width: 1024px) {
    .seo-feature-list {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
    }

    .seo-target-list {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
    }

    .seo-steps {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
    }
}

/* ===== SNS Share Buttons & Toast Styles ===== */

/* Common SNS Buttons Styling */
.sns-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: none;
    cursor: pointer;
    text-decoration: none;
    font-size: 0.875rem;
    transition: var(--transition);
    color: #ffffff;
    outline: none;
    padding: 0;
    line-height: 1;
}

.sns-btn:hover {
    transform: translateY(-2px) scale(1.06);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.sns-btn:active {
    transform: translateY(0) scale(0.95);
}

/* Brand Colors */
.sns-x {
    background: #0f1419;
    color: #ffffff;
}
.sns-x:hover {
    background: #000000;
}

.sns-line {
    background: #06C755;
    color: #ffffff;
}
.sns-line:hover {
    background: #05b34c;
}

.sns-insta {
    background: linear-gradient(45deg, #f09433 0%, #e6683c 25%, #dc2743 50%, #cc2366 75%, #bc1888 100%);
    color: #ffffff;
}
.sns-insta:hover {
    filter: brightness(1.1);
}

.sns-copy {
    background: var(--primary-blue);
    color: #ffffff;
}
.sns-copy:hover {
    background: #1d4ed8;
}

/* Responsive Header Share */
@media (max-width: 640px) {
    .header-sns-share .sns-share-label {
        display: none;
    }
    .header-sns-share {
        padding: 4px 8px;
    }
    .sns-btn {
        width: 28px;
        height: 28px;
        font-size: 0.75rem;
    }
    .header-nav .nav-link {
        padding: 6px 12px;
        font-size: 0.8rem;
    }
}

/* Footer & Footer SNS Container */
.site-footer {
    margin-top: 40px;
    padding: 32px 0 24px;
    border-top: 1px solid var(--border-light);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 24px;
}

.footer-sns-container {
    width: 100%;
    max-width: 560px;
    background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
    border: 1px solid var(--border-light);
    border-radius: var(--border-radius-md);
    padding: 24px 28px;
    box-shadow: var(--shadow-sm);
    text-align: center;
}

.sns-prompt-box {
    margin-bottom: 18px;
}

.sns-prompt-title {
    font-size: 1.05rem;
    font-weight: 800;
    color: var(--text-main);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin-bottom: 6px;
}

.sns-prompt-title i {
    color: #ef4444;
}

.sns-prompt-desc {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin: 0;
    line-height: 1.5;
}

.footer-sns-group {
    display: flex;
    justify-content: center;
    gap: 10px;
    flex-wrap: wrap;
}

.sns-btn.footer-btn {
    width: auto;
    height: 42px;
    padding: 0 16px;
    border-radius: 100px;
    font-size: 0.875rem;
    font-weight: 700;
    gap: 8px;
    box-shadow: var(--shadow-sm);
}

.footer-nav {
    display: flex;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

.footer-nav a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.875rem;
    font-weight: 600;
    transition: var(--transition);
}

.footer-nav a:hover {
    color: var(--primary-blue);
}

.copyright {
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* Toast Notification Styles */
.toast-container {
    position: fixed;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(15, 23, 42, 0.94);
    color: #ffffff;
    padding: 12px 24px;
    border-radius: 100px;
    font-size: 0.875rem;
    font-weight: 600;
    box-shadow: 0 12px 28px -5px rgba(0, 0, 0, 0.35);
    backdrop-filter: blur(8px);
    z-index: 9999;
    display: flex;
    align-items: center;
    gap: 10px;
    transition: opacity 0.3s cubic-bezier(0.4, 0, 0.2, 1), transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    pointer-events: auto;
    max-width: 90vw;
    text-align: center;
}

.toast-container.hidden {
    opacity: 0;
    transform: translate(-50%, 20px);
    pointer-events: none;
}