/* ========================================
   NihonGo! (日本GO!) — Design System
   ======================================== */

/* ─── IMPORTS ─── */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=Noto+Sans+Bengali:wght@300;400;500;600;700;800&display=swap');

/* ─── CSS VARIABLES ─── */
:root {
    /* Colors */
    --bg-primary: #0a0a0f;
    --bg-secondary: #0f0f1a;
    --bg-tertiary: #141425;
    --surface: rgba(255, 255, 255, 0.04);
    --surface-hover: rgba(255, 255, 255, 0.08);
    --border: rgba(255, 255, 255, 0.08);
    --border-hover: rgba(255, 255, 255, 0.15);
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    
    /* Accent Colors */
    --purple: #a855f7;
    --pink: #ec4899;
    --cyan: #06b6d4;
    --green: #22c55e;
    --amber: #f59e0b;
    --red: #ef4444;
    --blue: #3b82f6;
    --orange: #f97316;
    
    /* Gradients */
    --gradient-main: linear-gradient(135deg, #a855f7, #ec4899, #06b6d4);
    --gradient-purple-pink: linear-gradient(135deg, #a855f7, #ec4899);
    --gradient-pink-cyan: linear-gradient(135deg, #ec4899, #06b6d4);
    --gradient-purple-cyan: linear-gradient(135deg, #a855f7, #06b6d4);
    
    /* Glass */
    --glass-bg: rgba(255, 255, 255, 0.04);
    --glass-bg-hover: rgba(255, 255, 255, 0.08);
    --glass-border: rgba(255, 255, 255, 0.08);
    --glass-blur: 16px;
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-glow-purple: 0 0 30px rgba(168, 85, 247, 0.3);
    --shadow-glow-pink: 0 0 30px rgba(236, 72, 153, 0.3);
    --shadow-glow-cyan: 0 0 30px rgba(6, 182, 212, 0.3);
    
    /* Spacing */
    --nav-height: 72px;
    --sidebar-width: 280px;
    
    /* Fonts */
    --font-primary: 'Noto Sans Bengali', 'Inter', sans-serif;
    --font-display: 'Inter', 'Noto Sans Bengali', sans-serif;
    
    /* Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 400ms ease;
}

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

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-primary);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
}

a {
    color: inherit;
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
    color: inherit;
}

input, select, textarea {
    font-family: inherit;
    color: inherit;
}

ul, ol {
    list-style: none;
}

/* ─── WATERMARK BACKGROUND ─── */
.watermark-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    font-size: 180px;
    font-weight: 900;
    color: rgba(255, 255, 255, 0.02);
    line-height: 1.2;
    word-wrap: break-word;
    pointer-events: none;
    z-index: 0;
    overflow: hidden;
    user-select: none;
    letter-spacing: 30px;
}

/* ─── LAYOUT ─── */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.section {
    position: relative;
    padding: 100px 0;
    z-index: 1;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-badge {
    display: inline-block;
    padding: 6px 16px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-full);
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.section-title {
    font-family: var(--font-display);
    font-size: clamp(1.8rem, 4vw, 2.5rem);
    font-weight: 800;
    line-height: 1.3;
    margin-bottom: 16px;
}

.section-subtitle {
    font-size: 1.05rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

.w-full {
    width: 100%;
}

/* ─── GRADIENT TEXT ─── */
.gradient-text {
    background: var(--gradient-main);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ─── GLASS CARD ─── */
.glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    transition: all var(--transition-base);
}

.glass-card:hover {
    background: var(--glass-bg-hover);
    border-color: var(--border-hover);
}

/* ─── BUTTONS ─── */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 24px;
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    font-weight: 600;
    transition: all var(--transition-base);
    cursor: pointer;
    white-space: nowrap;
    position: relative;
    overflow: hidden;
}

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

.btn-sm {
    padding: 8px 16px;
    font-size: 0.85rem;
}

/* Gradient Button */
.btn-gradient {
    background: var(--gradient-purple-pink);
    color: white;
    border: none;
    box-shadow: 0 4px 15px rgba(168, 85, 247, 0.3);
}

.btn-gradient:hover {
    box-shadow: 0 6px 25px rgba(168, 85, 247, 0.5), 0 0 40px rgba(236, 72, 153, 0.3);
    transform: translateY(-2px);
}

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

/* Outline Button */
.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border);
}

.btn-outline:hover {
    border-color: var(--purple);
    background: rgba(168, 85, 247, 0.1);
    color: var(--purple);
}

/* Ghost Button */
.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
    padding: 10px 16px;
}

.btn-ghost:hover {
    color: var(--text-primary);
}

/* Nav Buttons */
.btn-outline-nav {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border);
    padding: 8px 20px;
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-weight: 600;
}

.btn-outline-nav:hover {
    border-color: var(--purple);
    background: rgba(168, 85, 247, 0.1);
}

.btn-gradient-nav {
    background: var(--gradient-purple-pink);
    color: white;
    padding: 8px 20px;
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-weight: 600;
    box-shadow: 0 2px 10px rgba(168, 85, 247, 0.3);
}

.btn-gradient-nav:hover {
    box-shadow: 0 4px 20px rgba(168, 85, 247, 0.5);
    transform: translateY(-1px);
}

/* ─── NAVBAR ─── */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(10, 10, 15, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    transition: all var(--transition-base);
}

.navbar.scrolled {
    background: rgba(10, 10, 15, 0.95);
    box-shadow: var(--shadow-md);
}

.nav-container {
    max-width: 1300px;
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-left {
    flex-shrink: 0;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-icon {
    font-size: 1.6rem;
}

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

.logo-name {
    font-family: var(--font-display);
    font-size: 1.3rem;
    font-weight: 800;
    background: var(--gradient-main);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2;
}

.logo-tagline {
    font-size: 0.65rem;
    color: var(--text-muted);
    letter-spacing: 0.5px;
    font-weight: 500;
}

.nav-center {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link {
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.nav-link:hover, .nav-link.active {
    color: var(--text-primary);
    background: var(--surface);
}

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

.lang-toggle {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.lang-toggle:hover {
    color: var(--text-primary);
    background: var(--surface);
}

/* Mobile Menu Button */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
    width: 40px;
    height: 40px;
    align-items: center;
    justify-content: center;
}

.mobile-menu-btn span {
    width: 22px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all var(--transition-base);
}

.mobile-menu-btn.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-btn.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* Mobile Menu */
.mobile-menu {
    display: none;
    flex-direction: column;
    padding: 16px 24px 24px;
    background: rgba(10, 10, 15, 0.98);
    border-bottom: 1px solid var(--border);
}

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

.mobile-link {
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    font-weight: 500;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.mobile-link:hover, .mobile-link.active {
    color: var(--text-primary);
    background: var(--surface);
}

.mobile-auth {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-top: 16px;
    padding-top: 16px;
    border-top: 1px solid var(--border);
}

/* ─── FOOTER ─── */
.footer {
    position: relative;
    z-index: 1;
    border-top: 1px solid var(--border);
    padding: 60px 0 30px;
    background: var(--bg-secondary);
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand {
    max-width: 320px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 16px;
}

.footer-logo .logo-name {
    font-size: 1.3rem;
}

.footer-desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 20px;
}

.footer-social {
    display: flex;
    gap: 12px;
}

.social-link {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
    background: var(--surface);
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.social-link:hover {
    background: var(--surface-hover);
    color: var(--purple);
    transform: translateY(-2px);
}

.footer-links-col h4 {
    font-size: 0.95rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.footer-links-col a {
    display: block;
    padding: 6px 0;
    font-size: 0.9rem;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    padding-top: 24px;
    border-top: 1px solid var(--border);
    text-align: center;
}

.footer-bottom p {
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* ─── FORM ELEMENTS ─── */
.form-group {
    margin-bottom: 20px;
}

.form-label {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.form-input {
    width: 100%;
    padding: 12px 16px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.95rem;
    transition: all var(--transition-fast);
    outline: none;
}

.form-input:focus {
    border-color: var(--purple);
    background: rgba(168, 85, 247, 0.05);
    box-shadow: 0 0 0 3px rgba(168, 85, 247, 0.15);
}

.form-input::placeholder {
    color: var(--text-muted);
}

/* Phone Input Group */
.phone-input-group {
    display: flex;
    gap: 8px;
}

.country-code-select {
    width: 110px;
    padding: 12px 8px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.9rem;
    outline: none;
    cursor: pointer;
    -webkit-appearance: none;
    appearance: none;
}

.country-code-select:focus {
    border-color: var(--purple);
}

.country-code-select option {
    background: var(--bg-primary);
    color: var(--text-primary);
}

.phone-input-group .form-input {
    flex: 1;
}

/* ─── ANIMATIONS ─── */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes float {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(5deg); }
}

@keyframes pulse-glow {
    0%, 100% { box-shadow: 0 0 20px rgba(168, 85, 247, 0.2); }
    50% { box-shadow: 0 0 40px rgba(168, 85, 247, 0.4); }
}

@keyframes shimmer {
    0% { background-position: -200% center; }
    100% { background-position: 200% center; }
}

@keyframes slideInLeft {
    from { opacity: 0; transform: translateX(-30px); }
    to { opacity: 1; transform: translateX(0); }
}

@keyframes slideInRight {
    from { opacity: 0; transform: translateX(30px); }
    to { opacity: 1; transform: translateX(0); }
}

@keyframes scaleIn {
    from { opacity: 0; transform: scale(0.9); }
    to { opacity: 1; transform: scale(1); }
}

@keyframes fillBar {
    from { width: 0%; }
    to { width: var(--fill-width); }
}

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

.animate-fade-in-up {
    animation: fadeInUp 0.6s ease forwards;
}

.animate-fade-in {
    animation: fadeIn 0.6s ease forwards;
}

/* ─── SCROLLBAR ─── */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* ─── RESPONSIVE ─── */
@media (max-width: 1024px) {
    .container {
        padding: 0 20px;
    }
    
    .section {
        padding: 70px 0;
    }
}

@media (max-width: 768px) {
    .nav-center {
        display: none;
    }
    
    .nav-right .btn-outline-nav,
    .nav-right .btn-gradient-nav,
    .nav-right .lang-toggle {
        display: none;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .section {
        padding: 50px 0;
    }
    
    .section-header {
        margin-bottom: 40px;
    }
    
    .section-title {
        font-size: 1.6rem;
    }
    
    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 30px;
    }
    
    .footer-brand {
        grid-column: 1 / -1;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    
    .section-title {
        font-size: 1.4rem;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
    }
}