/* ==========================================
   🎨 CSS CUSTOM PROPERTIES (Design Tokens)
   ========================================== */
:root {
    /* Colors */
    --color-primary: #38bdf8;
    --color-primary-hover: #0ea5e9;
    --color-primary-dark: #0284c7;
    
    --color-bg-dark: #0f172a;
    --color-bg-card: #111827;
    --color-bg-input: #1e293b;
    
    --color-border: #1e293b;
    --color-border-hover: #334155;
    
    --color-text-primary: #ffffff;
    --color-text-secondary: #cbd5e1;
    --color-text-muted: #94a3b8;
    --color-text-dim: #64748b;
    --color-text-faint: #475569;
    
    /* Spacing */
    --spacing-xs: 5px;
    --spacing-sm: 10px;
    --spacing-md: 15px;
    --spacing-lg: 20px;
    --spacing-xl: 25px;
    --spacing-2xl: 30px;
    --spacing-3xl: 40px;
    --spacing-4xl: 60px;
    --spacing-5xl: 80px;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 10px;
    --radius-lg: 16px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.4s ease;
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 12px rgba(56, 189, 248, 0.3);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.3);
}

/* ==========================================
   🔄 GLOBAL RESETS & BASE
   ========================================== */
html {
    scroll-behavior: smooth;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', Arial, sans-serif;
    background: var(--color-bg-dark);
    color: var(--color-text-primary);
    font-size: 16px;
    overflow-x: hidden;
    line-height: 1.6;
}

/* ==========================================
   🧭 NAVIGATION (Responsive & Fluid)
   ========================================== */
nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) 5%;
    background: var(--color-bg-card);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: transform var(--transition-normal);
}

nav.header-hidden {
    transform: translateY(-100%);
}

.logo {
    font-size: 24px;
    font-weight: bold;
    color: var(--color-primary);
    white-space: nowrap;
    text-decoration: none;
    transition: opacity var(--transition-fast);
}

.logo:hover {
    opacity: 0.8;
}

/* Desktop Navigation Container */
.desktop-nav {
    display: flex;
    align-items: center;
    gap: var(--spacing-2xl);
}

.desktop-nav .nav-links {
    display: flex;
    gap: var(--spacing-lg);
    align-items: center;
}

.desktop-nav .nav-links a {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: 15px;
    transition: color var(--transition-normal);
    white-space: nowrap;
    position: relative;
}

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

.desktop-nav .nav-links a:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 4px;
    border-radius: 4px;
}

.desktop-nav .nav-auth {
    display: flex;
    gap: 12px;
    align-items: center;
}

/* Hamburger Button (Hidden on Desktop) */
.hamburger {
    display: none;
    background: none;
    border: none;
    color: var(--color-primary);
    font-size: 28px;
    cursor: pointer;
    z-index: 1002;
    padding: var(--spacing-xs);
    transition: transform var(--transition-fast);
}

.hamburger:hover {
    transform: scale(1.1);
}

.hamburger:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
    border-radius: 4px;
}

/* Mobile Menu Drawer (Hidden on Desktop) */
.mobile-menu {
    display: none;
}

/* ==========================================
   🎨 BUTTONS (Colorful & Boxed)
   ========================================== */
.btn-outline {
    padding: var(--spacing-sm) var(--spacing-lg);
    border: 2px solid var(--color-primary);
    border-radius: var(--radius-md);
    color: var(--color-primary);
    text-decoration: none;
    font-size: 14px;
    font-weight: 600;
    transition: all var(--transition-normal);
    background: transparent;
    white-space: nowrap;
    display: inline-block;
    text-align: center;
    cursor: pointer;
}

.btn-outline:hover {
    background: var(--color-primary);
    color: var(--color-bg-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-outline:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

.btn-solid, .btn {
    padding: var(--spacing-sm) 24px;
    background: var(--color-primary);
    border: 2px solid var(--color-primary);
    border-radius: var(--radius-md);
    color: var(--color-bg-dark);
    text-decoration: none;
    font-size: 14px;
    font-weight: bold;
    transition: all var(--transition-normal);
    cursor: pointer;
    white-space: nowrap;
    display: inline-block;
    text-align: center;
}

.btn-solid:hover, .btn:hover {
    background: var(--color-primary-hover);
    border-color: var(--color-primary-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-solid:focus, .btn:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

.btn-solid:active, .btn:active {
    transform: translateY(0);
}

/* ==========================================
   📦 BOXED CARDS (Dashboard & Auth)
   ========================================== */
.auth-card, .dash-card, .tutor-card, .feature-card, .booking-card {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl) var(--spacing-xl);
    transition: transform var(--transition-normal), 
                box-shadow var(--transition-normal), 
                border-color var(--transition-normal);
}

.auth-card:hover, .dash-card:hover, .tutor-card:hover, .feature-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-primary);
    box-shadow: var(--shadow-lg);
}

/* ==========================================
   🏠 HERO & SECTIONS
   ========================================== */
.hero {
    min-height: 90vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: var(--spacing-4xl) var(--spacing-lg);
}

.hero h1 {
    font-size: 56px;
    font-weight: bold;
    margin-bottom: var(--spacing-lg);
    line-height: 1.2;
    background: linear-gradient(135deg, var(--color-primary) 0%, #818cf8 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    max-width: 650px;
    font-size: 20px;
    line-height: 1.7;
    color: var(--color-text-secondary);
    margin-bottom: 35px;
}

.features, .how-it-works, .cta, .tutors-section, .dashboard {
    padding: var(--spacing-5xl) 5%;
}

.features, .cta {
    background: var(--color-bg-card);
    text-align: center;
}

.features h2, .how-it-works h2, .cta h2 {
    font-size: 40px;
    margin-bottom: 50px;
    color: var(--color-text-primary);
}

/* ==========================================
   📐 GRIDS (Auto-responsive)
   ========================================== */
.features-grid, .dashboard-grid, .tutors-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-xl);
    max-width: 1200px;
    margin: 0 auto;
}

.feature-icon, .dash-icon, .tutor-avatar {
    font-size: 40px;
    margin-bottom: var(--spacing-md);
}

.feature-card h3, .dash-card h3, .tutor-card h3 {
    font-size: 20px;
    margin-bottom: 12px;
    color: var(--color-primary);
}

.feature-card p, .dash-card p, .tutor-card p {
    color: var(--color-text-muted);
    font-size: 15px;
    line-height: 1.6;
}

/* ==========================================
   📝 FORMS & INPUTS
   ========================================== */
.auth-section {
    min-height: 90vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: var(--spacing-3xl) var(--spacing-lg);
}

.auth-card {
    width: 100%;
    max-width: 440px;
}

.auth-card h2 {
    font-size: 30px;
    margin-bottom: 8px;
}

.auth-sub {
    color: var(--color-text-muted);
    font-size: 15px;
    margin-bottom: 35px;
}

.auth-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

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

.form-group label {
    font-size: 14px;
    color: var(--color-text-secondary);
    font-weight: 500;
}

.form-group input,
.form-group select,
.form-group textarea {
    padding: 12px var(--spacing-md);
    background: var(--color-bg-input);
    border: 1px solid var(--color-border-hover);
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    font-size: 15px;
    outline: none;
    transition: border var(--transition-normal), box-shadow var(--transition-normal);
    font-family: inherit;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.1);
}

.form-group select option {
    background: var(--color-bg-input);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--color-text-dim);
}

.full-width {
    width: 100%;
    padding: 14px;
    font-size: 16px;
    margin-top: var(--spacing-xs);
}

.auth-footer {
    text-align: center;
    margin-top: var(--spacing-xl);
    color: var(--color-text-dim);
    font-size: 14px;
}

.auth-footer a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.auth-footer a:hover {
    color: var(--color-primary-hover);
    text-decoration: underline;
}

.auth-footer a:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
    border-radius: 2px;
}

/* ==========================================
   💬 CHAT & OTHER COMPONENTS
   ========================================== */
.chat-section {
    padding: var(--spacing-3xl) var(--spacing-lg);
    display: flex;
    justify-content: center;
}

.chat-container {
    width: 100%;
    max-width: 800px;
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    display: flex;
    flex-direction: column;
    height: 80vh;
}

.chat-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-lg) var(--spacing-xl);
    border-bottom: 1px solid var(--color-border);
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: var(--spacing-xl);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.chat-messages::-webkit-scrollbar {
    width: 8px;
}

.chat-messages::-webkit-scrollbar-track {
    background: var(--color-bg-input);
    border-radius: 4px;
}

.chat-messages::-webkit-scrollbar-thumb {
    background: var(--color-border-hover);
    border-radius: 4px;
}

.chat-messages::-webkit-scrollbar-thumb:hover {
    background: var(--color-text-dim);
}

.message-bubble {
    max-width: 70%;
    padding: 12px 16px;
    border-radius: var(--radius-lg);
    font-size: 15px;
    line-height: 1.6;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.bot-message .message-bubble {
    background: var(--color-bg-input);
    color: #e2e8f0;
    border-bottom-left-radius: 4px;
}

.user-message .message-bubble {
    background: var(--color-primary);
    color: var(--color-bg-dark);
    border-bottom-right-radius: 4px;
    align-self: flex-end;
}

.chat-input-area {
    display: flex;
    gap: var(--spacing-sm);
    padding: var(--spacing-lg) var(--spacing-xl);
    border-top: 1px solid var(--color-border);
}

.chat-input-area input {
    flex: 1;
    padding: 12px 16px;
    background: var(--color-bg-input);
    border: 1px solid var(--color-border-hover);
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    font-size: 15px;
    outline: none;
    transition: border var(--transition-normal);
}

.chat-input-area input:focus {
    border-color: var(--color-primary);
}

/* ==========================================
   🦶 FOOTER
   ========================================== */
footer {
    background: #0a0f1a;
    padding: var(--spacing-4xl) 5% var(--spacing-2xl);
    border-top: 1px solid var(--color-border);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-3xl);
    max-width: 1200px;
    margin: 0 auto var(--spacing-3xl);
}

.footer-brand .logo {
    font-size: 22px;
    margin-bottom: var(--spacing-sm);
}

.footer-brand p {
    color: var(--color-text-faint);
    font-size: 14px;
    line-height: 1.6;
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer-links h4 {
    color: var(--color-text-primary);
    font-size: 15px;
    margin-bottom: var(--spacing-xs);
}

.footer-links a {
    color: var(--color-text-faint);
    text-decoration: none;
    font-size: 14px;
    transition: color var(--transition-normal);
}

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

.footer-links a:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
    border-radius: 2px;
}

.footer-bottom {
    border-top: 1px solid var(--color-border);
    padding-top: var(--spacing-xl);
    text-align: center;
    color: var(--color-border-hover);
    font-size: 13px;
    max-width: 1200px;
    margin: 0 auto;
}

/* ==========================================
   🛠️ UTILITY CLASSES
   ========================================== */
.text-center {
    text-align: center;
}

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

.text-right {
    text-align: right;
}

.mt-1 { margin-top: var(--spacing-sm); }
.mt-2 { margin-top: var(--spacing-lg); }
.mt-3 { margin-top: var(--spacing-xl); }
.mt-4 { margin-top: var(--spacing-2xl); }

.mb-1 { margin-bottom: var(--spacing-sm); }
.mb-2 { margin-bottom: var(--spacing-lg); }
.mb-3 { margin-bottom: var(--spacing-xl); }
.mb-4 { margin-bottom: var(--spacing-2xl); }

.hidden {
    display: none !important;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ==========================================
   📏 TABLET / SMALLER DESKTOP (Max 1024px)
   ========================================== */
@media (max-width: 1024px) {
    nav {
        flex-wrap: wrap;
    }

    /* Stack links under the logo, but keep auth buttons visible */
    .desktop-nav {
        width: 100%;
        flex-direction: column;
        align-items: center;
        gap: var(--spacing-md);
        margin-top: var(--spacing-md);
        padding-top: var(--spacing-md);
        border-top: 1px solid var(--color-border);
    }

    .desktop-nav .nav-links {
        flex-wrap: wrap;
        justify-content: center;
        gap: var(--spacing-md);
    }

    .desktop-nav .nav-auth {
        display: flex;
        gap: var(--spacing-sm);
    }
    
    .hero h1 {
        font-size: 42px;
    }
    
    .hero p {
        font-size: 18px;
    }
    
    .features h2, .how-it-works h2, .cta h2 {
        font-size: 32px;
    }
}

/* ==========================================
   📱 STRICT MOBILE OVERRIDES (Max 768px)
   ========================================== */
@media (max-width: 768px) {
    /* Hide desktop nav completely */
    .desktop-nav {
        display: none !important;
    }

    /* Show Hamburger on the right */
    .hamburger {
        display: block;
    }

    /* Ensure logo stays on left, hamburger on right */
    nav {
        justify-content: space-between;
        padding: var(--spacing-md) var(--spacing-lg);
    }

    /* Slide-out Drawer (Takes ~1/3 of screen) */
    .mobile-menu {
        display: flex;
        flex-direction: column;
        position: fixed;
        top: 0;
        right: -100%;
        width: 75vw;
        max-width: 320px;
        height: 100vh;
        background: var(--color-bg-card);
        border-left: 1px solid var(--color-border);
        padding: var(--spacing-5xl) var(--spacing-xl) var(--spacing-xl);
        transition: right var(--transition-normal);
        z-index: 1001;
        gap: var(--spacing-2xl);
        box-shadow: -5px 0 20px rgba(0, 0, 0, 0.5);
    }

    .mobile-menu.active {
        right: 0;
    }

    /* FORCE STACKING & WHITE TEXT */
    .mobile-menu .nav-links {
        display: flex !important;
        flex-direction: column !important;
        align-items: flex-start !important;
        width: 100% !important;
        gap: 0 !important;
    }

    .mobile-menu .nav-links a {
        font-size: 18px;
        font-weight: 500;
        color: var(--color-text-primary) !important;
        padding: 14px 0;
        width: 100%;
        text-decoration: none;
        border-bottom: 1px solid rgba(255, 255, 255, 0.08);
        transition: all var(--transition-fast);
    }

    .mobile-menu .nav-links a:hover {
        color: var(--color-primary) !important;
        padding-left: var(--spacing-sm);
    }

    .mobile-menu .nav-auth {
        display: flex !important;
        flex-direction: column !important;
        width: 100% !important;
        gap: 12px !important;
        margin-top: var(--spacing-sm);
    }

    .mobile-menu .nav-auth .btn-outline,
    .mobile-menu .nav-auth .btn-solid {
        width: 100%;
        text-align: center;
        padding: 14px;
        font-size: 16px;
        font-weight: 600;
    }

    /* Hero adjustments */
    .hero {
        min-height: 80vh;
        padding: var(--spacing-3xl) var(--spacing-md);
    }
    
    .hero h1 {
        font-size: 32px;
    }
    
    .hero p {
        font-size: 16px;
    }

    /* ==========================================
       🦶 COMPACT MOBILE FOOTER
       ========================================== */
    footer {
        padding: var(--spacing-lg) var(--spacing-sm) 0 var(--spacing-sm) !important;
    }

    .footer-content {
        grid-template-columns: repeat(3, 1fr) !important;
        gap: var(--spacing-md);
        padding: 0;
        text-align: left;
    }

    .footer-links {
        align-items: flex-start;
    }

    .footer-links h4 {
        font-size: 14px;
        margin-bottom: 8px;
        color: var(--color-primary);
    }

    .footer-links a {
        font-size: 12px;
        padding: 3px 0;
    }

    .footer-bottom {
        padding: var(--spacing-md) var(--spacing-sm);
        font-size: 11px;
    }
}

/* ==========================================
   🖨️ PRINT STYLES
   ========================================== */
@media print {
    nav, footer, .hamburger, .mobile-menu, .chat-input-area {
        display: none !important;
    }
    
    body {
        background: white;
        color: black;
    }
    
    .hero, .features, .how-it-works, .cta {
        padding: 20px 0;
    }
    
    a {
        color: black;
        text-decoration: underline;
    }
}