/* ===== CSS Variables ===== */
:root {
    --primary: #3b82f6;
    --primary-dark: #2563eb;
    --secondary: #64748b;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --info: #06b6d4;
    --bg: #f1f5f9;
    --surface: #ffffff;
    --surface-hover: #f8fafc;
    --ink: #1e293b;
    --muted: #64748b;
    --rule: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --radius-sm: 4px;
    --radius: 8px;
    --radius-lg: 12px;
    --header-height: 56px;
    --footer-height: 48px;
    --transition: all 0.2s ease;
}

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

html, body {
    height: 100%;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    font-size: 14px;
    line-height: 1.5;
    color: var(--ink);
    background: var(--bg);
    overflow: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ===== Layout ===== */
body {
    display: flex;
    flex-direction: column;
}

.main-container {
    flex: 1;
    display: flex;
    overflow: hidden;
    position: relative;
    padding-top: var(--header-height);
    padding-bottom: var(--footer-height);
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 8px 16px;
    border: none;
    border-radius: var(--radius);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
}

.btn:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow);
}

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

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

.btn-primary:hover {
    background: var(--primary-dark);
}

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

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

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

/* ===== Form Elements ===== */
.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    margin-bottom: 6px;
    font-weight: 500;
    color: var(--ink);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--rule);
    border-radius: var(--radius);
    font-size: 14px;
    transition: var(--transition);
    background: var(--surface);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgb(59 130 246 / 0.1);
}

/* ===== Modal Base ===== */
.modal {
    position: fixed;
    inset: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgb(0 0 0 / 0.5);
    backdrop-filter: blur(4px);
    opacity: 1;
    transition: opacity 0.2s ease;
}

.modal.hidden {
    display: none;
    opacity: 0;
}

.modal-content {
    background: var(--surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    width: 90%;
    max-width: 480px;
    max-height: 85vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    animation: modalSlideIn 0.2s ease;
}

@keyframes modalSlideIn {
    from {
        transform: translateY(-20px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    border-bottom: 1px solid var(--rule);
}

.modal-header h3 {
    font-size: 16px;
    font-weight: 600;
}

.modal-body {
    padding: 20px;
    overflow-y: auto;
    flex: 1;
}

.modal-footer {
    display: flex;
    gap: 8px;
    justify-content: flex-end;
    padding: 12px 20px;
    border-top: 1px solid var(--rule);
    background: var(--surface-hover);
}

.close-btn {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: none;
    background: transparent;
    border-radius: var(--radius);
    font-size: 20px;
    color: var(--muted);
    cursor: pointer;
    transition: var(--transition);
}

.close-btn:hover {
    background: var(--bg);
    color: var(--ink);
}

/* ===== Utility Classes ===== */
.hidden {
    display: none !important;
}

.admin-only {
    display: none;
}

body.is-admin .admin-only {
    display: inline-flex;
}

/* ===== Scrollbar ===== */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--rule);
    border-radius: 3px;
}

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

/* ===== Selection ===== */
::selection {
    background: rgb(59 130 246 / 0.2);
}