/* ===== STYLES PREMIUM DE LA PAGE D'ACCUEIL ===== */

/* Variables CSS avancées pour les thèmes */
:root {
    --primary-color: #667eea;
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --secondary-color: #f093fb;
    --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --accent-color: #4facfe;
    --accent-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --success-color: #43e97b;
    --success-gradient: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
    --warning-color: #fa709a;
    --warning-gradient: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
    --danger-color: #ff6b6b;
    --danger-gradient: linear-gradient(135deg, #ff6b6b 0%, #ee5a24 100%);
    
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --border-color: #e2e8f0;
    --shadow-color: rgba(0, 0, 0, 0.08);
    --shadow-color-hover: rgba(0, 0, 0, 0.12);
    
    --glass-bg: rgba(255, 255, 255, 0.25);
    --glass-border: rgba(255, 255, 255, 0.18);
    --glass-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.37);
    
    --calculator-bg: #ffffff;
    --button-bg: #f8fafc;
    --button-hover: #e2e8f0;
    --display-bg: #f8fafc;
}

/* Thème sombre premium */
[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --border-color: #334155;
    --shadow-color: rgba(0, 0, 0, 0.3);
    --shadow-color-hover: rgba(0, 0, 0, 0.4);
    
    --glass-bg: rgba(30, 41, 59, 0.25);
    --glass-border: rgba(51, 65, 85, 0.18);
    
    --calculator-bg: #1e293b;
    --button-bg: #334155;
    --button-hover: #475569;
    --display-bg: #0f172a;
}

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

body {
    font-family: 'Inter', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    overflow-x: hidden;
    line-height: 1.6;
}

/* ===== NAVIGATION PREMIUM ===== */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 1px 3px 0 var(--shadow-color);
}

[data-theme="dark"] .navbar {
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 16px;
    position: relative;
}

.logo-img {
    width: 48px;
    height: 48px;
    filter: drop-shadow(0 4px 12px rgba(102, 126, 234, 0.3));
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.logo-img:hover {
    transform: scale(1.1) rotate(5deg);
    filter: drop-shadow(0 8px 24px rgba(102, 126, 234, 0.4));
}

.logo-text {
    font-size: 28px;
    font-weight: 800;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
}

.nav-menu {
    display: flex;
    gap: 8px;
    position: relative;
}

.nav-link {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 600;
    padding: 12px 20px;
    border-radius: 50px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    font-size: 15px;
    letter-spacing: -0.01em;
}

.nav-link::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: var(--primary-gradient);
    transition: left 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: -1;
}

.nav-link:hover::before,
.nav-link.active::before {
    left: 0;
}

.nav-link:hover,
.nav-link.active {
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.3);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 24px;
    height: 4px;
    background: var(--primary-gradient);
    border-radius: 2px;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; transform: translateX(-50%) scale(1); }
    50% { opacity: 0.7; transform: translateX(-50%) scale(1.1); }
}

.nav-toggle {
    display: none;
    width: 40px;
    height: 40px;
    border: none;
    border-radius: 12px;
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    font-size: 18px;
    border: 1px solid var(--glass-border);
}

.nav-toggle:hover {
    background: var(--primary-gradient);
    color: white;
    transform: scale(1.05);
}

/* ===== SECTION HÉRO PREMIUM ===== */

.hero-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 120px 24px 80px;
    background: var(--bg-primary);
    position: relative;
    overflow: hidden;
}

.hero-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 80%, rgba(102, 126, 234, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(240, 147, 251, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(79, 172, 254, 0.1) 0%, transparent 50%);
    animation: float 20s ease-in-out infinite;
}

.hero-section::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="%23e2e8f0" stroke-width="0.3" opacity="0.5"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
    animation: slide 30s linear infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    33% { transform: translateY(-20px) rotate(1deg); }
    66% { transform: translateY(10px) rotate(-1deg); }
}

@keyframes slide {
    0% { transform: translateX(0) translateY(0); }
    100% { transform: translateX(-10px) translateY(-10px); }
}

.hero-content {
    flex: 1;
    max-width: 650px;
    z-index: 2;
    position: relative;
}

.hero-logo {
    margin-bottom: 40px;
    position: relative;
}

.hero-logo::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 160px;
    height: 160px;
    background: var(--primary-gradient);
    border-radius: 50%;
    filter: blur(40px);
    opacity: 0.3;
    animation: pulse-glow 3s ease-in-out infinite;
}

@keyframes pulse-glow {
    0%, 100% { opacity: 0.3; transform: translate(-50%, -50%) scale(1); }
    50% { opacity: 0.6; transform: translate(-50%, -50%) scale(1.1); }
}

.hero-logo-img {
    width: 140px;
    height: 140px;
    filter: drop-shadow(0 20px 40px rgba(102, 126, 234, 0.4));
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    z-index: 1;
}

.hero-logo-img:hover {
    transform: scale(1.1) rotate(10deg);
    filter: drop-shadow(0 30px 60px rgba(102, 126, 234, 0.6));
}

.hero-title {
    font-size: 5rem;
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: 24px;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.03em;
    position: relative;
}

.hero-title::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 120px;
    height: 6px;
    background: var(--primary-gradient);
    border-radius: 3px;
    animation: slideIn 1s ease-out 0.5s both;
}

@keyframes slideIn {
    from { width: 0; opacity: 0; }
    to { width: 120px; opacity: 1; }
}

.hero-subtitle {
    font-size: 1.75rem;
    color: var(--text-secondary);
    margin-bottom: 48px;
    line-height: 1.5;
    font-weight: 400;
    max-width: 540px;
}

.hero-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
    margin-bottom: 60px;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 28px;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: 20px;
    border: 1px solid var(--glass-border);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.feature-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: var(--primary-gradient);
    transition: left 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: -1;
    opacity: 0.1;
}

.feature-item:hover::before {
    left: 0;
}

.feature-item:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 25px 50px var(--shadow-color-hover);
    border-color: var(--primary-color);
}

.feature-item i {
    font-size: 2.5rem;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transition: all 0.3s ease;
}

.feature-item:hover i {
    transform: scale(1.2) rotate(5deg);
}

.feature-item span {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-primary);
    transition: color 0.3s ease;
}

.feature-item:hover span {
    color: var(--primary-color);
}

.hero-buttons {
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    padding: 18px 36px;
    border: none;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: 700;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    letter-spacing: -0.01em;
    text-transform: uppercase;
    font-size: 14px;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

.btn:hover::before {
    left: 100%;
}

.btn-primary {
    background: var(--primary-gradient);
    color: white;
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.3);
}

.btn-primary:hover {
    transform: translateY(-4px) scale(1.05);
    box-shadow: 0 15px 35px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
    box-shadow: 0 8px 25px var(--shadow-color);
}

.btn-secondary:hover {
    background: var(--secondary-gradient);
    color: white;
    border-color: transparent;
    transform: translateY(-4px) scale(1.05);
    box-shadow: 0 15px 35px rgba(240, 147, 251, 0.4);
}

.btn i {
    font-size: 1.2rem;
    transition: transform 0.3s ease;
}

.btn:hover i {
    transform: scale(1.2);
}

/* ===== SECTION VISUELLE PREMIUM ===== */

.hero-visual {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 2;
    position: relative;
}

.calculator-preview {
    background: var(--calculator-bg);
    border-radius: 30px;
    padding: 40px;
    box-shadow: 
        0 40px 80px var(--shadow-color-hover),
        0 0 0 1px var(--border-color),
        inset 0 1px 0 rgba(255, 255, 255, 0.1);
    transform: perspective(1200px) rotateY(-20deg) rotateX(15deg);
    transition: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    animation: float-calculator 8s ease-in-out infinite;
    position: relative;
    overflow: hidden;
}

.calculator-preview::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: conic-gradient(from 0deg, transparent, rgba(102, 126, 234, 0.1), transparent);
    animation: rotate 10s linear infinite;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

@keyframes float-calculator {
    0%, 100% { 
        transform: perspective(1200px) rotateY(-20deg) rotateX(15deg) translateY(0px); 
    }
    50% { 
        transform: perspective(1200px) rotateY(-15deg) rotateX(10deg) translateY(-30px); 
    }
}

.calculator-preview:hover {
    transform: perspective(1200px) rotateY(-10deg) rotateX(5deg) scale(1.08);
    box-shadow: 
        0 60px 120px var(--shadow-color-hover),
        0 0 0 1px var(--primary-color),
        inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.preview-display {
    background: var(--display-bg);
    border-radius: 16px;
    padding: 20px;
    margin-bottom: 24px;
    text-align: right;
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--text-primary);
    border: 2px solid var(--border-color);
    box-shadow: inset 0 2px 4px var(--shadow-color);
    position: relative;
    overflow: hidden;
}

.preview-display::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary-gradient);
}

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

.preview-btn {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    font-size: 1.1rem;
}

.preview-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--primary-gradient);
    opacity: 0;
    transition: opacity 0.3s ease;
    z-index: -1;
}

.preview-btn:hover::before {
    opacity: 1;
}

.preview-btn:not(.operator):not(.equals) {
    background: var(--button-bg);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.preview-btn:not(.operator):not(.equals):hover {
    color: white;
    transform: translateY(-2px) scale(1.1);
    box-shadow: 0 8px 20px rgba(102, 126, 234, 0.3);
}

.preview-btn.operator {
    background: var(--warning-gradient);
    color: white;
    box-shadow: 0 4px 15px rgba(250, 112, 154, 0.3);
}

.preview-btn.operator:hover {
    transform: translateY(-2px) scale(1.1);
    box-shadow: 0 8px 25px rgba(250, 112, 154, 0.4);
}

.preview-btn.equals {
    background: var(--success-gradient);
    color: white;
    box-shadow: 0 4px 15px rgba(67, 233, 123, 0.3);
}

.preview-btn.equals:hover {
    transform: translateY(-2px) scale(1.1);
    box-shadow: 0 8px 25px rgba(67, 233, 123, 0.4);
}

.preview-btn.zero {
    grid-column: span 2;
    width: 108px;
}

/* ===== SECTIONS AVANCÉES ===== */

.calculator-section,
.settings-section,
.about-section {
    min-height: 100vh;
    padding: 120px 24px 80px;
    background: var(--bg-primary);
    position: relative;
}

.settings-header,
.about-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 60px;
    padding-bottom: 30px;
    border-bottom: 3px solid var(--border-color);
    position: relative;
}

.settings-header::after,
.about-header::after {
    content: '';
    position: absolute;
    bottom: -3px;
    left: 0;
    width: 100px;
    height: 3px;
    background: var(--primary-gradient);
    border-radius: 2px;
}

.settings-header h2,
.about-header h2 {
    font-size: 3rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 20px;
    font-weight: 800;
    letter-spacing: -0.02em;
}

.back-btn {
    width: 60px;
    height: 60px;
    border: none;
    border-radius: 50%;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    font-size: 1.4rem;
    border: 1px solid var(--glass-border);
    position: relative;
    overflow: hidden;
}

.back-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: var(--primary-gradient);
    transition: left 0.3s ease;
    z-index: -1;
}

.back-btn:hover::before {
    left: 0;
}

.back-btn:hover {
    color: white;
    transform: scale(1.1) rotate(-5deg);
    box-shadow: 0 15px 35px rgba(102, 126, 234, 0.4);
}

/* ===== CONTENU DES RÉGLAGES PREMIUM ===== */

.settings-container,
.about-container {
    max-width: 900px;
    margin: 0 auto;
}

.settings-content {
    display: flex;
    flex-direction: column;
    gap: 48px;
}

.settings-group {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: 24px;
    padding: 40px;
    border: 1px solid var(--glass-border);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.settings-group::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--primary-gradient);
    transform: scaleX(0);
    transition: transform 0.4s ease;
}

.settings-group:hover::before {
    transform: scaleX(1);
}

.settings-group:hover {
    transform: translateY(-8px);
    box-shadow: 0 25px 50px var(--shadow-color-hover);
    border-color: var(--primary-color);
}

.settings-group h3 {
    font-size: 1.8rem;
    color: var(--text-primary);
    margin-bottom: 32px;
    display: flex;
    align-items: center;
    gap: 20px;
    font-weight: 700;
}

.settings-group h3 i {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-size: 2rem;
}

.setting-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
    border-bottom: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.setting-item:last-child {
    border-bottom: none;
}

.setting-item:hover {
    background: rgba(102, 126, 234, 0.05);
    border-radius: 12px;
    padding-left: 16px;
    padding-right: 16px;
    margin-left: -16px;
    margin-right: -16px;
}

.setting-item label {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 1.1rem;
}

.setting-select {
    padding: 12px 20px;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 1rem;
    min-width: 180px;
    transition: all 0.3s ease;
    cursor: pointer;
}

.setting-select:hover {
    border-color: var(--primary-color);
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.1);
}

.setting-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.setting-range {
    width: 180px;
    margin: 0 20px;
    -webkit-appearance: none;
    appearance: none;
    height: 8px;
    border-radius: 4px;
    background: var(--border-color);
    outline: none;
    cursor: pointer;
}

.setting-range::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--primary-gradient);
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
    transition: all 0.3s ease;
}

.setting-range::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
}

/* ===== TOGGLE SWITCH PREMIUM ===== */

.toggle-switch {
    position: relative;
    width: 70px;
    height: 36px;
}

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

.toggle-switch label {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--border-color);
    transition: .4s cubic-bezier(0.4, 0, 0.2, 1);
    border-radius: 36px;
    position: relative;
}

.toggle-switch label:before {
    position: absolute;
    content: "";
    height: 28px;
    width: 28px;
    left: 4px;
    bottom: 4px;
    background: white;
    transition: .4s cubic-bezier(0.4, 0, 0.2, 1);
    border-radius: 50%;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.toggle-switch input:checked + label {
    background: var(--primary-gradient);
}

.toggle-switch input:checked + label:before {
    transform: translateX(34px);
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.3);
}

/* ===== ACTIONS DES RÉGLAGES PREMIUM ===== */

.settings-actions {
    display: flex;
    gap: 24px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 40px;
}

.settings-actions .btn {
    min-width: 160px;
    justify-content: center;
}

/* ===== SECTION À PROPOS PREMIUM ===== */

.about-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 60px;
    align-items: start;
}

.about-logo-img {
    width: 240px;
    height: 240px;
    filter: drop-shadow(0 20px 40px rgba(102, 126, 234, 0.4));
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
}

.about-logo-img:hover {
    transform: scale(1.1) rotate(10deg);
    filter: drop-shadow(0 30px 60px rgba(102, 126, 234, 0.6));
}

.about-info h3 {
    font-size: 2.5rem;
    color: var(--text-primary);
    margin-bottom: 24px;
    font-weight: 800;
    letter-spacing: -0.02em;
}

.about-info p {
    font-size: 1.2rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 36px;
}

.version-info {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 28px;
    border-radius: 16px;
    margin-bottom: 36px;
    border: 1px solid var(--glass-border);
    position: relative;
    overflow: hidden;
}

.version-info::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--success-gradient);
}

.version-info p {
    margin-bottom: 12px;
    color: var(--text-primary);
    font-weight: 600;
}

.features-list {
    margin-bottom: 36px;
}

.features-list h4 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 20px;
    font-weight: 700;
}

.features-list ul {
    list-style: none;
    padding: 0;
}

.features-list li {
    padding: 12px 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: 32px;
    font-size: 1.1rem;
    transition: all 0.3s ease;
}

.features-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    background: var(--success-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: bold;
    font-size: 1.2rem;
}

.features-list li:hover {
    color: var(--text-primary);
    transform: translateX(8px);
}

.contact-info h4 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 20px;
    font-weight: 700;
}

.contact-info p {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 16px;
    color: var(--text-secondary);
    font-size: 1.1rem;
    transition: all 0.3s ease;
}

.contact-info p:hover {
    color: var(--primary-color);
    transform: translateX(8px);
}

.contact-info i {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    width: 24px;
    font-size: 1.2rem;
}

/* ===== RESPONSIVE PREMIUM ===== */

@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .nav-toggle {
        display: block;
    }
    
    .hero-section {
        flex-direction: column;
        text-align: center;
        gap: 60px;
        padding: 100px 20px 60px;
    }
    
    .hero-title {
        font-size: 3.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.4rem;
    }
    
    .hero-features {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .calculator-preview {
        transform: none;
        animation: none;
        padding: 30px;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 40px;
    }
    
    .settings-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .setting-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 16px;
    }
    
    .settings-header h2,
    .about-header h2 {
        font-size: 2.5rem;
    }
}

@media (max-width: 480px) {
    .nav-container {
        padding: 0 20px;
    }
    
    .hero-section {
        padding: 80px 16px 40px;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .btn {
        padding: 16px 28px;
        font-size: 13px;
    }
    
    .calculator-preview {
        padding: 24px;
    }
    
    .preview-btn {
        width: 40px;
        height: 40px;
        font-size: 1rem;
    }
    
    .preview-btn.zero {
        width: 92px;
    }
    
    .settings-group {
        padding: 24px;
    }
    
    .settings-header h2,
    .about-header h2 {
        font-size: 2rem;
    }
}

/* ===== ANIMATIONS D'ENTRÉE ===== */

.feature-item,
.settings-group,
.about-content {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s ease-out forwards;
}

.feature-item:nth-child(1) { animation-delay: 0.1s; }
.feature-item:nth-child(2) { animation-delay: 0.2s; }
.feature-item:nth-child(3) { animation-delay: 0.3s; }
.feature-item:nth-child(4) { animation-delay: 0.4s; }

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

/* ===== EFFETS DE SCROLL ===== */

.scroll-reveal {
    opacity: 0;
    transform: translateY(50px);
    transition: all 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

.scroll-reveal.revealed {
    opacity: 1;
    transform: translateY(0);
}

/* ===== CURSOR PERSONNALISÉ ===== */

.custom-cursor {
    width: 20px;
    height: 20px;
    background: var(--primary-gradient);
    border-radius: 50%;
    position: fixed;
    pointer-events: none;
    z-index: 9999;
    transition: all 0.1s ease;
    mix-blend-mode: difference;
}

.custom-cursor.hover {
    transform: scale(2);
    background: var(--accent-gradient);
}