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

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    transition: background-color 0.3s ease, color 0.3s ease;
}

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

a:hover {
    text-decoration: underline;
}

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

/* ===== Theme Variables ===== */
:root {
    /* Light Mode (default) */
    --bg-primary: #FFFFFF;
    --bg-secondary: #F8F9FA;
    --bg-accent: #FFF0F5;
    --bg-card: #FFFFFF;
    --text-primary: #1A1A2E;
    --text-secondary: #555555;
    --text-muted: #999999;
    --color-primary: #F2A7C3;
    --color-secondary: #87CEEB;
    --color-accent: #E91E63;
    --color-success: #4CAF50;
    --color-error: #F44336;
    --color-warning: #FF9800;
    --border-color: #E0E0E0;
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --border-radius-lg: 16px;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
}

[data-theme="dark"] {
    --bg-primary: #0D0D1A;
    --bg-secondary: #1A1A2E;
    --bg-accent: #16213E;
    --bg-card: #1A1A2E;
    --text-primary: #E0E0E0;
    --text-secondary: #A0A0A0;
    --text-muted: #666666;
    --color-primary: #BB86FC;
    --color-secondary: #03DAC6;
    --color-accent: #FF4081;
    --color-success: #00E676;
    --color-error: #FF5252;
    --color-warning: #FFD740;
    --border-color: #2A2A3E;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.5);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.6);
}

/* ===== Typography ===== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-primary);
}

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

p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

/* ===== Layout ===== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

.page-wrapper {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.main-content {
    flex: 1;
    padding: 2rem 0;
}

/* ===== Components ===== */

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--border-radius-sm);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
}

.btn:hover {
    text-decoration: none;
    transform: translateY(-1px);
}

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

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.btn-primary {
    background: var(--color-accent);
    color: #FFFFFF;
}

.btn-primary:hover {
    filter: brightness(1.1);
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

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

.btn-accent {
    background: linear-gradient(135deg, #667EEA, #764BA2);
    color: white;
    border: none;
}

.btn-accent:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

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

.btn-ghost:hover {
    background: var(--bg-secondary);
}

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

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

.btn-block {
    width: 100%;
}

/* Cards */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
}

/* Form Elements */
.form-group {
    margin-bottom: 1.25rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
}

.form-input {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    font-size: 1rem;
    background: var(--bg-primary);
    color: var(--text-primary);
    transition: border-color 0.2s ease;
}

.form-input:focus {
    outline: none;
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px rgba(233, 30, 99, 0.1);
}

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

textarea.form-input {
    resize: vertical;
    min-height: 100px;
}

/* OTP Input */
.otp-input-group {
    display: flex;
    gap: 0.5rem;
    justify-content: center;
}

.otp-digit {
    width: 3rem;
    height: 3.5rem;
    text-align: center;
    font-size: 1.5rem;
    font-weight: 700;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    background: var(--bg-primary);
    color: var(--text-primary);
    transition: border-color 0.2s ease;
}

.otp-digit:focus {
    outline: none;
    border-color: var(--color-accent);
}

/* Toast */
.toast-container {
    position: fixed;
    top: 1rem;
    right: 1rem;
    z-index: 9999;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.toast {
    padding: 0.75rem 1.25rem;
    border-radius: var(--border-radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    animation: slideIn 0.3s ease;
    max-width: 360px;
}

.toast-success {
    background: var(--color-success);
    color: #FFFFFF;
}

.toast-error {
    background: var(--color-error);
    color: #FFFFFF;
}

.toast-info {
    background: var(--color-secondary);
    color: #1A1A2E;
}

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

/* Navbar */
.navbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
}

.navbar-brand {
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--text-primary);
    text-decoration: none;
}

.navbar-brand:hover {
    text-decoration: none;
}

.navbar-nav {
    display: flex;
    align-items: center;
    gap: 1rem;
    list-style: none;
}

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    text-decoration: none;
    padding: 0.5rem;
    border-radius: var(--border-radius-sm);
    transition: color 0.2s, background 0.2s;
}

.nav-link:hover {
    color: var(--text-primary);
    background: var(--bg-secondary);
    text-decoration: none;
}

.nav-link.active {
    color: var(--color-accent);
}

/* Theme Toggle */
.theme-toggle {
    background: none;
    border: 1px solid var(--border-color);
    border-radius: 50%;
    width: 2.25rem;
    height: 2.25rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.125rem;
    color: var(--text-primary);
    transition: background 0.2s;
}

.theme-toggle:hover {
    background: var(--bg-secondary);
}

/* Credits Badge */
.credits-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    padding: 0.25rem 0.75rem;
    background: var(--bg-accent);
    border-radius: 999px;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-accent);
}

/* Loading Spinner */
.spinner {
    width: 1.5rem;
    height: 1.5rem;
    border: 3px solid var(--border-color);
    border-top-color: var(--color-accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* ===== Responsive ===== */
@media (max-width: 768px) {
    h1 { font-size: 1.75rem; }
    h2 { font-size: 1.5rem; }
    h3 { font-size: 1.25rem; }

    .container {
        padding: 0 0.75rem;
    }

    .navbar-nav {
        gap: 0.5rem;
    }
}

@media (min-width: 768px) {
    .container {
        padding: 0 1.5rem;
    }
}

@media (min-width: 1024px) {
    .container {
        padding: 0 2rem;
    }
}