/* BitChat APK - Main Stylesheet */

/* CSS Variables for Theme Colors */
:root {
    /* Primary Colors */
    --c-accent: #00E0B8;
    --c-accent-hover: #1AFFC9;
    --c-accent-light: #4DFFD1;
    --c-accent-dark: #00B894;
    
    /* Background Colors */
    --c-bg-dark: #0A0A0A;
    --c-bg-darker: #050505;
    --c-bg-light: #1A1A1A;
    --c-bg-lighter: #2A2A2A;
    
    /* Text Colors */
    --c-text: #FFFFFF;
    --c-text-sec: #B0B0B0;
    --c-text-muted: #808080;
    --c-text-dark: #000000;
    
    /* Status Colors */
    --c-success: #00E0B8;
    --c-warning: #FFB800;
    --c-error: #FF4757;
    --c-info: #3742FA;
    
    /* Shadows */
    --shadow-light: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-medium: 0 4px 16px rgba(0, 0, 0, 0.15);
    --shadow-heavy: 0 8px 32px rgba(0, 0, 0, 0.2);
    --shadow-accent: 0 4px 16px rgba(0, 224, 184, 0.3);
    
    /* Transitions */
    --transition: all 0.3s ease;
    --transition-fast: all 0.15s ease;
    --transition-slow: all 0.5s ease;
}

/* Light Theme Variables */
[data-theme="light"] {
    --c-bg-dark: #FFFFFF;
    --c-bg-darker: #F8F9FA;
    --c-bg-light: #F1F3F4;
    --c-bg-lighter: #E8EAED;
    --c-text: #1A1A1A;
    --c-text-sec: #5F6368;
    --c-text-muted: #9AA0A6;
    --c-text-dark: #000000;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--c-text);
    background: linear-gradient(135deg, var(--c-bg-dark) 0%, var(--c-bg-darker) 100%);
    min-height: 100vh;
    overflow-x: hidden;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
    color: var(--c-text);
}

h1 {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 800;
}

h2 {
    font-size: clamp(1.5rem, 4vw, 2.5rem);
}

h3 {
    font-size: clamp(1.25rem, 3vw, 2rem);
}

p {
    margin-bottom: 1rem;
    color: var(--c-text-sec);
    font-size: 1.1rem;
    line-height: 1.7;
}

a {
    color: var(--c-accent);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--c-accent-hover);
    text-decoration: underline;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Header & Navigation */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(10, 10, 10, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 224, 184, 0.1);
    z-index: 1000;
    transition: var(--transition);
}

[data-theme="light"] .header {
    background: rgba(255, 255, 255, 0.95);
    border-bottom: 1px solid rgba(0, 224, 184, 0.2);
}

.header.scrolled {
    background: rgba(10, 10, 10, 0.98);
    box-shadow: var(--shadow-medium);
}

[data-theme="light"] .header.scrolled {
    background: rgba(255, 255, 255, 0.98);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 0;
    position: relative;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--c-text);
    text-decoration: none;
}

.logo-text-full {
    color: var(--c-text);
    font-weight: 700;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    color: var(--c-text-sec);
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-link:hover {
    color: var(--c-accent);
    text-decoration: none;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--c-accent);
    transition: var(--transition);
}

.nav-link:hover::after {
    width: 100%;
}

/* Theme Toggle */
.theme-toggle {
    background: none;
    border: none;
    color: var(--c-text-sec);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    color: var(--c-accent);
    background: rgba(0, 224, 184, 0.1);
}

/* Mobile Navigation */
.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--c-text);
    transition: var(--transition);
}

/* Hero Section */
.hero {
    padding: 120px 0 80px;
    background: linear-gradient(135deg, var(--c-bg-dark) 0%, var(--c-bg-darker) 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 80%, rgba(0, 224, 184, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(26, 255, 201, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    position: relative;
    z-index: 2;
}

.hero-text h1 {
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, var(--c-accent) 0%, var(--c-accent-hover) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-text p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    color: var(--c-text-sec);
}

.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.app-screenshot {
    max-width: 100%;
    height: auto;
    border-radius: 20px;
    box-shadow: var(--shadow-heavy);
    transition: var(--transition);
}

.app-screenshot:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-accent);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    font-size: 1rem;
    gap: 0.5rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--c-accent) 0%, var(--c-accent-hover) 100%);
    color: var(--c-text-dark);
    box-shadow: var(--shadow-accent);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 224, 184, 0.4);
    color: var(--c-text-dark);
    text-decoration: none;
}

.btn-secondary {
    background: transparent;
    color: var(--c-accent);
    border: 2px solid var(--c-accent);
}

.btn-secondary:hover {
    background: var(--c-accent);
    color: var(--c-text-dark);
    text-decoration: none;
}

/* Sections */
.section {
    padding: 80px 0;
}

.section-title {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title h2 {
    margin-bottom: 1rem;
    color: var(--c-text);
}

.section-title p {
    font-size: 1.2rem;
    color: var(--c-text-sec);
    max-width: 600px;
    margin: 0 auto;
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.feature-card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(0, 224, 184, 0.1);
    border-radius: 20px;
    padding: 2rem;
    transition: var(--transition);
    backdrop-filter: blur(10px);
}

[data-theme="light"] .feature-card {
    background: rgba(255, 255, 255, 0.8);
    border: 1px solid rgba(0, 224, 184, 0.2);
}

.feature-card:hover {
    transform: translateY(-5px);
    border-color: var(--c-accent);
    box-shadow: var(--shadow-accent);
}

.feature-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--c-accent) 0%, var(--c-accent-hover) 100%);
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    color: var(--c-text-dark);
    font-size: 1.5rem;
}

.feature-card h3 {
    margin-bottom: 1rem;
    color: var(--c-text);
}

.feature-card p {
    color: var(--c-text-sec);
    margin-bottom: 0;
}

/* Download Section */
.download-section {
    background: linear-gradient(135deg, var(--c-bg-light) 0%, var(--c-bg-lighter) 100%);
    text-align: center;
}

[data-theme="light"] .download-section {
    background: linear-gradient(135deg, var(--c-bg-lighter) 0%, var(--c-bg-light) 100%);
}

.download-info {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(0, 224, 184, 0.1);
    border-radius: 20px;
    padding: 2rem;
    margin: 2rem 0;
    backdrop-filter: blur(10px);
}

[data-theme="light"] .download-info {
    background: rgba(255, 255, 255, 0.8);
    border: 1px solid rgba(0, 224, 184, 0.2);
}

.download-instructions {
    text-align: left;
    max-width: 600px;
    margin: 2rem auto;
}

.download-instructions ol {
    margin-left: 1.5rem;
}

.download-instructions li {
    margin-bottom: 0.5rem;
    color: var(--c-text-sec);
}

/* Footer */
.footer {
    background: var(--c-bg-darker);
    border-top: 1px solid rgba(0, 224, 184, 0.1);
    padding: 3rem 0 1rem;
    margin-top: 4rem;
}

[data-theme="light"] .footer {
    background: var(--c-bg-lighter);
    border-top: 1px solid rgba(0, 224, 184, 0.2);
}

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

.footer-section h3 {
    margin-bottom: 1rem;
    color: var(--c-accent);
}

.footer-section p,
.footer-section a {
    color: var(--c-text-sec);
    margin-bottom: 0.5rem;
    display: block;
}

.footer-section a:hover {
    color: var(--c-accent);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 1rem;
    text-align: center;
    color: var(--c-text-muted);
}

[data-theme="light"] .footer-bottom {
    border-top: 1px solid rgba(0, 0, 0, 0.1);
}

/* Animations */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }
    
    .nav-menu {
        position: fixed;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--c-bg-dark);
        flex-direction: column;
        padding: 2rem;
        gap: 1rem;
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }
    
    [data-theme="light"] .nav-menu {
        background: var(--c-bg-light);
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }
    
    .hero-content {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .section {
        padding: 60px 0;
    }
    
    h1 {
        font-size: 2.5rem;
    }
    
    h2 {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .btn {
        padding: 0.6rem 1.5rem;
        font-size: 0.9rem;
    }
    
    .hero {
        padding: 100px 0 60px;
    }
    
    .section {
        padding: 40px 0;
    }
}

/* Utility Classes */
.text-center {
    text-align: center;
}

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

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

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.hidden {
    display: none;
}

.visible {
    display: block;
}