/* ===== CSS Variables ===== */
:root {
    --primary: #6c63ff;
    --primary-dark: #5a52d9;
    --secondary: #1a1a2e;
    --secondary-light: #16213e;
    --accent: #0f3460;
    --text: #333;
    --text-light: #666;
    --text-muted: #999;
    --white: #ffffff;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --success: #10b981;
    --error: #ef4444;
    --warning: #f59e0b;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --radius: 8px;
    --radius-lg: 12px;
    --transition: all 0.2s ease;
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    color: var(--text);
    line-height: 1.6;
    background: var(--gray-50);
    min-height: 100vh;
}

a {
    text-decoration: none;
    color: inherit;
}

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

/* ===== Typography ===== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    color: var(--secondary);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

@media (max-width: 768px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }
    h3 { font-size: 1.25rem; }
}

/* ===== Layout ===== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.section {
    padding: 5rem 0;
}

/* ===== Navigation ===== */
.navbar {
    background: var(--white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--secondary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo span {
    color: var(--primary);
}

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

.nav-links a {
    color: var(--text);
    font-weight: 500;
    transition: var(--transition);
}

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

.nav-auth {
    display: flex;
    align-items: center;
    gap: 1rem;
}

/* Mobile menu */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-menu-btn span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--secondary);
    margin: 5px 0;
    transition: var(--transition);
}

@media (max-width: 768px) {
    .mobile-menu-btn {
        display: block;
    }

    .nav-links, .nav-auth {
        display: none;
    }

    .navbar.open .nav-links {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--white);
        padding: 1rem;
        box-shadow: var(--shadow);
    }

    .navbar.open .nav-auth {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: calc(70px + 150px);
        left: 0;
        right: 0;
        background: var(--white);
        padding: 1rem;
        box-shadow: var(--shadow);
    }
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    border-radius: var(--radius);
    border: none;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-primary {
    background: var(--primary);
    color: var(--white);
}

.btn-primary:hover:not(:disabled) {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow);
}

.btn-secondary {
    background: var(--secondary);
    color: var(--white);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--secondary-light);
    transform: translateY(-1px);
}

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}

.btn-outline:hover:not(:disabled) {
    background: var(--primary);
    color: var(--white);
}

.btn-ghost {
    background: transparent;
    color: var(--text);
}

.btn-ghost:hover:not(:disabled) {
    background: var(--gray-100);
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.1rem;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn-icon {
    padding: 0.5rem;
    border-radius: 50%;
}

/* ===== Forms ===== */
.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text);
}

.form-input {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius);
    transition: var(--transition);
    background: var(--white);
}

.form-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(108, 99, 255, 0.1);
}

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

.form-error {
    color: var(--error);
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

.form-help {
    color: var(--text-muted);
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

/* ===== Cards ===== */
.card {
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.card-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--gray-200);
}

.card-body {
    padding: 1.5rem;
}

.card-footer {
    padding: 1.5rem;
    border-top: 1px solid var(--gray-200);
    background: var(--gray-50);
}

/* ===== Hero Section ===== */
.hero {
    background: linear-gradient(135deg, var(--secondary) 0%, var(--accent) 100%);
    color: var(--white);
    padding: 6rem 0;
    text-align: center;
}

.hero h1 {
    color: var(--white);
    margin-bottom: 1.5rem;
    font-size: 3rem;
}

.hero p {
    font-size: 1.25rem;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto 2rem;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

@media (max-width: 768px) {
    .hero {
        padding: 4rem 0;
    }

    .hero h1 {
        font-size: 2rem;
    }

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

/* ===== Features Section ===== */
.features {
    padding: 5rem 0;
}

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

.feature-card {
    text-align: center;
    padding: 2rem;
}

.feature-icon {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    color: var(--white);
    font-size: 1.5rem;
}

.feature-card h3 {
    margin-bottom: 0.75rem;
}

.feature-card p {
    color: var(--text-light);
}

/* ===== How It Works ===== */
.how-it-works {
    background: var(--gray-100);
    padding: 5rem 0;
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.step {
    text-align: center;
    position: relative;
}

.step-number {
    width: 48px;
    height: 48px;
    background: var(--primary);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    font-weight: 700;
    margin: 0 auto 1rem;
}

.step h4 {
    margin-bottom: 0.5rem;
}

.step p {
    color: var(--text-light);
    font-size: 0.95rem;
}

/* ===== Pricing Section ===== */
.pricing {
    padding: 5rem 0;
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.pricing-card {
    padding: 2.5rem;
    text-align: center;
    position: relative;
}

.pricing-card.featured {
    border: 2px solid var(--primary);
    transform: scale(1.05);
}

.pricing-card.featured::before {
    content: 'Most Popular';
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary);
    color: var(--white);
    padding: 0.25rem 1rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
}

.pricing-card h3 {
    margin-bottom: 0.5rem;
}

.pricing-card .price {
    font-size: 3rem;
    font-weight: 700;
    color: var(--secondary);
    margin: 1rem 0;
}

.pricing-card .price span {
    font-size: 1rem;
    color: var(--text-muted);
    font-weight: 400;
}

.pricing-features {
    list-style: none;
    margin: 2rem 0;
    text-align: left;
}

.pricing-features li {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--gray-200);
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.pricing-features li:last-child {
    border-bottom: none;
}

.pricing-features .check {
    color: var(--success);
    font-weight: bold;
}

/* ===== Auth Pages ===== */
.auth-page {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.auth-container {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
}

.auth-card {
    width: 100%;
    max-width: 420px;
}

.auth-card .card-body {
    padding: 2.5rem;
}

.auth-header {
    text-align: center;
    margin-bottom: 2rem;
}

.auth-header h1 {
    font-size: 1.75rem;
    margin-bottom: 0.5rem;
}

.auth-header p {
    color: var(--text-muted);
}

.auth-footer {
    text-align: center;
    margin-top: 1.5rem;
    color: var(--text-muted);
}

.auth-footer a {
    color: var(--primary);
    font-weight: 500;
}

.auth-footer a:hover {
    text-decoration: underline;
}

/* ===== Dashboard ===== */
.dashboard {
    padding: 2rem 0;
}

.dashboard-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.dashboard-header h1 {
    font-size: 1.75rem;
}

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

.stat-card {
    padding: 1.5rem;
}

.stat-card .stat-label {
    color: var(--text-muted);
    font-size: 0.875rem;
    margin-bottom: 0.5rem;
}

.stat-card .stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--secondary);
}

.stat-card .stat-help {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
}

.usage-bar {
    height: 8px;
    background: var(--gray-200);
    border-radius: 4px;
    margin-top: 1rem;
    overflow: hidden;
}

.usage-bar-fill {
    height: 100%;
    background: var(--primary);
    border-radius: 4px;
    transition: width 0.3s ease;
}

.usage-bar-fill.warning {
    background: var(--warning);
}

.usage-bar-fill.full {
    background: var(--error);
}

/* ===== Convert Page ===== */
.convert-page {
    padding: 2rem 0;
}

.upload-zone {
    border: 2px dashed var(--gray-300);
    border-radius: var(--radius-lg);
    padding: 3rem;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    background: var(--white);
}

.upload-zone:hover,
.upload-zone.dragover {
    border-color: var(--primary);
    background: rgba(108, 99, 255, 0.05);
}

.upload-zone.has-file {
    border-color: var(--success);
    border-style: solid;
}

.upload-icon {
    font-size: 3rem;
    color: var(--gray-300);
    margin-bottom: 1rem;
}

.upload-zone h3 {
    margin-bottom: 0.5rem;
}

.upload-zone p {
    color: var(--text-muted);
}

.upload-preview {
    max-width: 300px;
    margin: 1rem auto 0;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
}

.upload-preview img {
    width: 100%;
    display: block;
}

.convert-actions {
    margin-top: 2rem;
    text-align: center;
}

/* ===== Code Output ===== */
.code-output {
    margin-top: 2rem;
}

.code-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.code-tab {
    padding: 0.5rem 1rem;
    background: var(--gray-100);
    border: none;
    border-radius: var(--radius) var(--radius) 0 0;
    cursor: pointer;
    font-weight: 500;
    color: var(--text-muted);
    transition: var(--transition);
}

.code-tab.active {
    background: var(--secondary);
    color: var(--white);
}

.code-block {
    background: var(--secondary);
    border-radius: 0 var(--radius) var(--radius) var(--radius);
    overflow: hidden;
    position: relative;
}

.code-block pre {
    padding: 1.5rem;
    overflow-x: auto;
    color: #e0e0e0;
    font-family: 'Fira Code', 'Monaco', monospace;
    font-size: 0.875rem;
    line-height: 1.6;
    margin: 0;
}

.code-block code {
    font-family: inherit;
}

.copy-btn {
    position: absolute;
    top: 0.75rem;
    right: 0.75rem;
    background: rgba(255, 255, 255, 0.1);
    border: none;
    color: var(--white);
    padding: 0.5rem 1rem;
    border-radius: var(--radius);
    cursor: pointer;
    font-size: 0.875rem;
    transition: var(--transition);
}

.copy-btn:hover {
    background: rgba(255, 255, 255, 0.2);
}

.copy-btn.copied {
    background: var(--success);
}

/* ===== Loading States ===== */
.loading {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid transparent;
    border-top-color: currentColor;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

.skeleton {
    background: linear-gradient(90deg, var(--gray-200) 25%, var(--gray-100) 50%, var(--gray-200) 75%);
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
    border-radius: var(--radius);
}

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

/* ===== Toast Notifications ===== */
.toast-container {
    position: fixed;
    top: 1rem;
    right: 1rem;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.toast {
    background: var(--white);
    padding: 1rem 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    animation: slideIn 0.3s ease;
    max-width: 400px;
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

.toast.success {
    border-left: 4px solid var(--success);
}

.toast.error {
    border-left: 4px solid var(--error);
}

.toast.warning {
    border-left: 4px solid var(--warning);
}

.toast-close {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-muted);
    padding: 0.25rem;
    margin-left: auto;
}

/* ===== Footer ===== */
.footer {
    background: var(--secondary);
    color: var(--white);
    padding: 3rem 0 1.5rem;
    margin-top: auto;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    color: var(--white);
    margin-bottom: 1rem;
}

.footer-section a {
    display: block;
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 0.5rem;
    transition: var(--transition);
}

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

.footer-bottom {
    text-align: center;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.875rem;
}

/* ===== Utilities ===== */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

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

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

.hidden { display: none !important; }

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.gap-3 { gap: 1.5rem; }

/* ===== Premium Badge ===== */
.premium-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    background: linear-gradient(135deg, #fbbf24 0%, #f59e0b 100%);
    color: #78350f;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
}

/* ===== Responsive Adjustments ===== */
@media (max-width: 768px) {
    .section {
        padding: 3rem 0;
    }

    .pricing-card.featured {
        transform: none;
    }

    .dashboard-header {
        flex-direction: column;
        align-items: flex-start;
    }
}