* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #2c3e50;
    --secondary: #34495e;
    --accent-beginner: #27ae60;
    --accent-intermediate: #f39c12;
    --accent-expert: #8e44ad;
    --bg-light: #ecf0f1;
    --bg-dark: #1a1a2e;
    --text-light: #333;
    --text-dark: #fff;
    --shadow: 0 4px 6px rgba(0,0,0,0.1);

    /* Mode clair (par défaut) */
    --body-bg: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --card-bg: #ffffff;
    --card-text: #333;
    --header-bg: linear-gradient(135deg, rgba(0,0,0,0.8), rgba(0,0,0,0.6));
}

/* Mode Nuit */
body.dark-mode {
    --body-bg: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    --card-bg: #0f3460;
    --card-text: #e8e8e8;
    --header-bg: linear-gradient(135deg, #0a0e27 0%, #16213e 100%);
    --primary: #3d5a80;
    --secondary: #98c1d9;
    --bg-light: #293241;
    --text-light: #e8e8e8;
    --shadow: 0 4px 6px rgba(0,0,0,0.5);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-light);
    background: var(--body-bg);
    min-height: 100vh;
    transition: all 0.3s ease;
}

header {
    background: var(--header-bg);
    color: var(--text-dark);
    padding: 2rem 1rem;
    text-align: center;
    box-shadow: var(--shadow);
    position: relative;
}

/* Bouton Mode Nuit */
.dark-mode-toggle {
    position: absolute;
    top: 1rem;
    right: 8rem;
    background: rgba(255,255,255,0.2);
    border: 2px solid rgba(255,255,255,0.5);
    color: white;
    padding: 0.8rem 1.5rem;
    border-radius: 25px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: bold;
    transition: all 0.3s;
    backdrop-filter: blur(10px);
}

.dark-mode-toggle:hover {
    background: rgba(255,255,255,0.3);
    transform: scale(1.05);
}

/* Bouton Langue */
.lang-toggle {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: rgba(255,255,255,0.2);
    border: 2px solid rgba(255,255,255,0.5);
    color: white;
    padding: 0.8rem 1.5rem;
    border-radius: 25px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: bold;
    transition: all 0.3s;
    backdrop-filter: blur(10px);
}

.lang-toggle:hover {
    background: rgba(255,255,255,0.3);
    transform: scale(1.05);
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
}

.subtitle {
    font-size: 1.2rem;
    opacity: 0.9;
    font-style: italic;
}

nav {
    background: var(--primary);
    padding: 1rem;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    gap: 2rem;
    justify-content: center;
}

nav a {
    color: var(--text-dark);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 5px;
    transition: all 0.3s;
    font-weight: 500;
}

nav a:hover, nav a.active {
    background: rgba(255,255,255,0.2);
    transform: translateY(-2px);
}

main {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 1rem;
}

.hero {
    background: var(--card-bg);
    color: var(--card-text);
    padding: 3rem 2rem;
    border-radius: 15px;
    margin-bottom: 3rem;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    text-align: center;
}

.hero h2 {
    color: var(--primary);
    font-size: 2rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.1rem;
    color: var(--secondary);
    max-width: 800px;
    margin: 0 auto;
}

.section-category {
    background: var(--card-bg);
    color: var(--card-text);
    padding: 3rem 2rem;
    border-radius: 15px;
    margin-bottom: 3rem;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.section-category h2 {
    color: var(--card-text);
    font-size: 2rem;
    margin-bottom: 1rem;
    text-align: center;
}

.intro {
    text-align: center;
    color: var(--card-text);
    opacity: 0.8;
    font-size: 1.1rem;
    margin-bottom: 2rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.level-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.card {
    background: var(--bg-light);
    color: var(--card-text);
    border-radius: 10px;
    padding: 2rem;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
    border-top: 5px solid;
}

.card.beginner {
    border-color: var(--accent-beginner);
}

.card.intermediate {
    border-color: var(--accent-intermediate);
}

.card.expert {
    border-color: var(--accent-expert);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.card h3 {
    color: var(--primary);
    font-size: 1.5rem;
}

.badge {
    background: var(--primary);
    color: white;
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: bold;
}

.card ul {
    list-style: none;
    margin: 1.5rem 0;
}

.card ul li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
    color: var(--secondary);
}

.card ul li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--accent-beginner);
    font-weight: bold;
}

.card.intermediate ul li:before {
    color: var(--accent-intermediate);
}

.card.expert ul li:before {
    color: var(--accent-expert);
}

.btn {
    display: inline-block;
    padding: 0.8rem 2rem;
    border-radius: 25px;
    text-decoration: none;
    font-weight: bold;
    text-align: center;
    transition: all 0.3s;
    color: white;
    margin-top: 1rem;
}

.btn-beginner {
    background: var(--accent-beginner);
}

.btn-intermediate {
    background: var(--accent-intermediate);
}

.btn-expert {
    background: var(--accent-expert);
}

.btn:hover {
    transform: scale(1.05);
    box-shadow: 0 5px 15px rgba(0,0,0,0.3);
}

.tools {
    background: var(--card-bg);
    color: var(--card-text);
    padding: 3rem 2rem;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.tools h2 {
    color: var(--primary);
    font-size: 2rem;
    margin-bottom: 2rem;
    text-align: center;
}

.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.tool-card {
    background: var(--bg-light);
    color: var(--card-text);
    padding: 2rem;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 3px 10px rgba(0,0,0,0.1);
    transition: transform 0.3s;
}

.tool-card:hover {
    transform: translateY(-5px);
}

.tool-card h3 {
    color: var(--primary);
    margin-bottom: 1rem;
}

.tool-card p {
    color: var(--secondary);
    margin-bottom: 1rem;
}

.btn-small {
    display: inline-block;
    padding: 0.5rem 1.5rem;
    background: var(--primary);
    color: white;
    text-decoration: none;
    border-radius: 20px;
    transition: all 0.3s;
}

.btn-small:hover {
    background: var(--secondary);
    transform: scale(1.05);
}

footer {
    background: rgba(0,0,0,0.8);
    color: var(--text-dark);
    text-align: center;
    padding: 2rem 1rem;
    margin-top: 3rem;
}

/* Styles pour les pages de contenu */
.content-page {
    background: var(--card-bg);
    color: var(--card-text);
    padding: 3rem 2rem;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    margin: 2rem auto;
    max-width: 1000px;
}

.breadcrumb {
    background: var(--bg-light);
    padding: 1rem;
    border-radius: 5px;
    margin-bottom: 2rem;
}

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

.breadcrumb a:hover {
    text-decoration: underline;
}

.lesson {
    margin: 2rem 0;
    padding: 2rem;
    background: var(--bg-light);
    color: var(--card-text);
    border-radius: 10px;
    border-left: 5px solid var(--accent-beginner);
}

.rune-grid, .letter-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.rune-card, .letter-card {
    background: var(--card-bg);
    color: var(--card-text);
    padding: 1.5rem;
    border-radius: 10px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.1);
    text-align: center;
    transition: transform 0.3s;
}

.rune-card:hover, .letter-card:hover {
    transform: scale(1.05);
}

.rune-symbol, .letter-symbol {
    font-size: 3rem;
    font-weight: bold;
    color: var(--primary);
    margin-bottom: 0.5rem;
}

.rune-name, .letter-name {
    font-size: 1.2rem;
    font-weight: bold;
    color: var(--secondary);
    margin-bottom: 0.5rem;
}

.rune-meaning, .letter-value {
    color: var(--text-light);
    font-style: italic;
}

.navigation-buttons {
    display: flex;
    justify-content: space-between;
    margin-top: 3rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.progress-bar {
    background: var(--bg-light);
    height: 10px;
    border-radius: 10px;
    margin: 2rem 0;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-beginner), var(--accent-intermediate));
    transition: width 0.5s;
}

.exercise {
    background: #fff3cd;
    color: #333;
    padding: 1.5rem;
    border-radius: 10px;
    margin: 1.5rem 0;
    border-left: 5px solid var(--accent-intermediate);
}

body.dark-mode .exercise {
    background: rgba(243, 156, 18, 0.2);
    color: var(--text-light);
}

.tip {
    background: #d1ecf1;
    color: #333;
    padding: 1.5rem;
    border-radius: 10px;
    margin: 1.5rem 0;
    border-left: 5px solid #0c5460;
}

body.dark-mode .tip {
    background: rgba(52, 152, 219, 0.2);
    color: var(--text-light);
    border-left-color: #3498db;
}

@media (max-width: 768px) {
    header h1 {
        font-size: 1.8rem;
    }

    .level-cards, .tools-grid {
        grid-template-columns: 1fr;
    }

    .navigation-buttons {
        flex-direction: column;
    }
}

/* === AMÉLIORATIONS MOBILE IPHONE === */
@media (max-width: 768px) {
    header {
        padding: 1rem 0.5rem 3.5rem;
    }

    header h1 {
        font-size: 1.5rem !important;
        padding: 0 0.5rem;
        margin-top: 3rem;
    }

    .subtitle {
        font-size: 1rem;
        padding: 0 0.5rem;
    }

    /* Repositionner les boutons en mode mobile */
    .dark-mode-toggle,
    .lang-toggle {
        position: fixed !important;
        top: auto !important;
        bottom: 1rem !important;
        padding: 0.6rem 1rem !important;
        font-size: 0.9rem !important;
        z-index: 1000;
    }

    .dark-mode-toggle {
        left: 1rem !important;
        right: auto !important;
    }

    .lang-toggle {
        right: 1rem !important;
        left: auto !important;
    }

    nav {
        padding: 0.5rem;
    }

    .nav-container {
        gap: 0.5rem;
        flex-wrap: wrap;
    }

    nav a {
        padding: 0.5rem 0.8rem;
        font-size: 0.9rem;
    }

    main {
        margin: 1rem auto;
        padding: 0 0.5rem;
    }

    .hero {
        padding: 1.5rem 1rem;
        margin-bottom: 1.5rem;
    }

    .hero h2 {
        font-size: 1.5rem;
    }

    .hero p {
        font-size: 1rem;
    }

    .section-category {
        padding: 1.5rem 1rem;
        margin-bottom: 1.5rem;
    }

    .section-category h2 {
        font-size: 1.5rem;
    }

    .intro {
        font-size: 1rem;
    }

    .level-cards, .tools-grid {
        grid-template-columns: 1fr !important;
        gap: 1rem;
    }

    .card {
        padding: 1.5rem;
    }

    .card h3 {
        font-size: 1.3rem;
    }

    .btn {
        padding: 0.7rem 1.5rem;
        font-size: 0.95rem;
    }

    .tools {
        padding: 1.5rem 1rem;
    }

    .tools h2 {
        font-size: 1.5rem;
    }

    .rune-grid, .letter-grid {
        grid-template-columns: 1fr !important;
        gap: 1rem;
    }

    .tool-card {
        padding: 1.5rem;
    }

    footer {
        padding: 1.5rem 1rem 4rem;
        margin-top: 2rem;
        font-size: 0.9rem;
    }
}

/* Améliorations tactiles pour mobile */
@media (hover: none) and (pointer: coarse) {
    .btn, .btn-small, nav a {
        min-height: 44px;
        display: inline-flex;
        align-items: center;
        justify-content: center;
    }
}