:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f5f5f5;
    --bg-card: #ffffff;
    --text-primary: #1a1a1a;
    --text-secondary: #666666;
    --border-color: #e0e0e0;
    --accent-color: #007bff;
    --accent-hover: #0056b3;
    --success-color: #28a745;
    --error-color: #dc3545;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 16px rgba(0, 0, 0, 0.15);
}

[data-theme="dark"] {
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --bg-card: #252525;
    --text-primary: #e0e0e0;
    --text-secondary: #a0a0a0;
    --border-color: #404040;
    --accent-color: #4a9eff;
    --accent-hover: #3a8eef;
    --success-color: #32cd32;
    --error-color: #ff6b6b;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-hover: 0 4px 16px rgba(0, 0, 0, 0.4);
}

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

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

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
}

#themeToggle {
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    cursor: pointer;
    font-size: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
}

#themeToggle:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow-hover);
}

[data-theme="dark"] .icon-sun {
    display: none;
}

[data-theme="light"] .icon-moon,
:root:not([data-theme]) .icon-moon {
    display: none;
}

.header {
    text-align: center;
    padding: 40px 0 20px;
}

.logo {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 10px;
    background: linear-gradient(135deg, var(--accent-color), var(--success-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.main-content {
    flex: 1;
    padding: 20px 0;
}

.card {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.card:hover {
    box-shadow: var(--shadow-hover);
}

.card h2 {
    margin-bottom: 20px;
    font-size: 1.5rem;
    color: var(--text-primary);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-primary);
}

.form-group input {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    background: var(--bg-secondary);
    color: var(--text-primary);
    transition: all 0.3s ease;
}

.form-group input:focus {
    outline: none;
    border-color: var(--accent-color);
    background: var(--bg-card);
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-block;
}

.btn-primary {
    background: var(--accent-color);
    color: white;
    width: 100%;
}

.btn-primary:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.btn-copy {
    background: var(--success-color);
    color: white;
    white-space: nowrap;
}

.btn-copy:hover {
    background: #218838;
}

.btn-small {
    padding: 6px 12px;
    font-size: 0.875rem;
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #545b62;
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
}

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

.btn-danger:hover {
    background: #c82333;
}

.result {
    margin-top: 30px;
}

.result-success h3 {
    color: var(--success-color);
    margin-bottom: 15px;
}

.short-url-box {
    display: flex;
    gap: 10px;
    margin-bottom: 15px;
}

.short-url-box input {
    flex: 1;
    padding: 12px 16px;
    border: 2px solid var(--success-color);
    border-radius: 8px;
    font-size: 1rem;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-weight: 600;
}

.result-comment {
    color: var(--text-secondary);
    font-style: italic;
}

.error {
    padding: 15px;
    background: #ffe6e6;
    border: 2px solid var(--error-color);
    border-radius: 8px;
    color: var(--error-color);
    margin-top: 20px;
}

[data-theme="dark"] .error {
    background: #3d1f1f;
}

.hidden {
    display: none !important;
}

.my-links {
    max-height: 500px;
    overflow-y: auto;
}

.empty-state {
    text-align: center;
    color: var(--text-secondary);
    padding: 40px 20px;
}

.link-item {
    padding: 15px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    margin-bottom: 15px;
    background: var(--bg-secondary);
    transition: all 0.3s ease;
}

.link-item:hover {
    border-color: var(--accent-color);
    box-shadow: var(--shadow);
}

.link-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: 10px;
    flex-wrap: wrap;
    gap: 10px;
}

.link-url {
    font-weight: 600;
    color: var(--accent-color);
    word-break: break-all;
}

.link-stats {
    display: flex;
    gap: 15px;
    margin-top: 10px;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.link-original {
    color: var(--text-secondary);
    font-size: 0.875rem;
    word-break: break-all;
    margin: 5px 0;
}

.link-comment {
    color: var(--text-secondary);
    font-style: italic;
    margin: 5px 0;
}

.link-actions {
    display: flex;
    gap: 10px;
    margin-top: 10px;
}

.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
}

.modal-content {
    background: var(--bg-card);
    border-radius: 12px;
    max-width: 800px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-hover);
}

.modal-large {
    max-width: 1200px;
}

.modal-header {
    padding: 20px 30px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-close {
    background: none;
    border: none;
    font-size: 2rem;
    cursor: pointer;
    color: var(--text-secondary);
    line-height: 1;
}

.modal-close:hover {
    color: var(--text-primary);
}

.modal-body {
    padding: 30px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.stat-card {
    background: var(--bg-secondary);
    padding: 20px;
    border-radius: 8px;
    text-align: center;
}

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

.stat-label {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-top: 5px;
}

.footer {
    text-align: center;
    padding: 30px 0;
    color: var(--text-secondary);
    border-top: 1px solid var(--border-color);
    margin-top: auto;
}

.admin-link {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
    margin-left: 15px;
}

.admin-link:hover {
    text-decoration: underline;
}

@media (max-width: 768px) {
    .container {
        padding: 10px;
    }

    .card {
        padding: 20px;
    }

    .logo {
        font-size: 2rem;
    }

    .short-url-box {
        flex-direction: column;
    }

    .link-header {
        flex-direction: column;
    }

    .stats-grid {
        grid-template-columns: 1fr;
    }
}