/* ========================================
   CCTV Calc - Design System
======================================== */

:root {
    --primary: #2563eb;
    --primary-light: #3b82f6;
    --primary-dark: #1d4ed8;

    --accent-teal: #0d9488;
    --accent-emerald: #059669;
    --accent-amber: #d97706;
    --accent-rose: #e11d48;

    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    --gray-900: #0f172a;

    --bg-primary: #ffffff;
    --bg-secondary: #eef2f7;
    --bg-tertiary: #f1f5f9;
    --surface: #ffffff;

    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #64748b;
    --text-light: #94a3b8;

    --border-light: #e2e8f0;
    --border-medium: #cbd5e1;

    --shadow-sm: 0 1px 2px rgb(0 0 0 / 0.06), 0 1px 3px rgb(0 0 0 / 0.04);
    --shadow-md: 0 4px 8px rgb(0 0 0 / 0.08), 0 2px 4px rgb(0 0 0 / 0.06);
    --shadow-lg: 0 8px 24px rgb(0 0 0 / 0.12), 0 4px 8px rgb(0 0 0 / 0.06);
    --shadow-inset: inset 0 2px 4px rgb(0 0 0 / 0.06);
    --shadow-inset-lg: inset 0 2px 6px rgb(0 0 0 / 0.1), inset 0 0 0 1px rgb(0 0 0 / 0.04);

    --radius-sm: 8px;
    --radius-md: 10px;
    --radius-lg: 14px;
    --radius-xl: 18px;
    --radius-full: 9999px;

    --transition-fast: 150ms ease;
    --transition-normal: 200ms ease;
    --transition-slow: 300ms ease;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
    font-family: 'Noto Sans KR', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-secondary);
    background-image:
        radial-gradient(circle at 20% 50%, rgba(37, 99, 235, 0.03) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(13, 148, 136, 0.03) 0%, transparent 50%);
    color: var(--text-primary);
    min-height: 100vh;
    font-size: 15px;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 800px;
    margin-top: 24px;
    margin-bottom: 40px;
    padding: 0 16px;
}

/* ========================================
   NAVIGATION
======================================== */

.navbar {
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(226, 232, 240, 0.6);
    padding: 8px 0;
    box-shadow: 0 1px 3px rgb(0 0 0 / 0.05);
}

.brand-logo {
    display: flex;
    align-items: center;
    gap: 8px;
}

.brand-icon {
    font-size: 1.25rem;
    color: var(--primary);
    filter: drop-shadow(0 1px 2px rgba(37, 99, 235, 0.3));
}

.brand-text {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.025em;
}

.navbar-nav .nav-link {
    padding: 6px 12px !important;
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--text-secondary) !important;
    border-radius: var(--radius-sm);
    transition: var(--transition-normal);
}

.navbar-nav .nav-link:hover {
    color: var(--primary) !important;
    background: rgba(37, 99, 235, 0.06);
}

.navbar-nav .nav-link i {
    font-size: 0.875rem;
}

.navbar-toggler {
    border: 1px solid var(--border-light);
    padding: 4px 8px;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
}

.navbar-toggler-icon {
    width: 1.2em;
    height: 1.2em;
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(15, 23, 42, 0.75)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
}

/* ========================================
   CARDS
======================================== */

.card {
    background: var(--surface);
    border: 1px solid rgba(226, 232, 240, 0.8);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    position: relative;
}

.card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.8), transparent);
    z-index: 1;
}

.card-header {
    background: linear-gradient(145deg, #1a1f35 0%, #0f172a 50%, #162032 100%);
    padding: 16px 20px;
    border-bottom: none;
    position: relative;
    overflow: hidden;
}

.card-header::after {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.1), transparent);
}

.card-header h5,
.card-header h4,
.card-header h3 {
    font-size: 1rem;
    font-weight: 700;
    color: white;
    margin-bottom: 2px;
    letter-spacing: -0.01em;
    text-shadow: 0 1px 2px rgba(0,0,0,0.3);
}

.card-header p {
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.75rem;
    margin: 0;
}

.card-body {
    padding: 20px;
    background: linear-gradient(180deg, #fafbfd 0%, #ffffff 30%);
}

.card-footer {
    background: linear-gradient(180deg, var(--bg-tertiary), #e8ecf2);
    border-top: 1px solid var(--border-light);
    padding: 10px 20px;
    color: var(--text-muted);
    font-size: 0.75rem;
}

/* ========================================
   CALCULATOR DISPLAY
======================================== */

.calc-display {
    background: linear-gradient(160deg, #0c1222 0%, #111827 40%, #0f172a 100%);
    border-radius: var(--radius-md);
    padding: 16px;
    margin-top: 16px;
    box-shadow: var(--shadow-inset-lg), 0 1px 0 rgba(255,255,255,0.05);
    border: 1px solid rgba(0,0,0,0.2);
    position: relative;
}

.calc-display::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    border-radius: var(--radius-md);
    background: linear-gradient(180deg, rgba(255,255,255,0.03) 0%, transparent 40%);
    pointer-events: none;
}

.calc-display .calc-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 10px;
}

.calc-display .calc-item {
    text-align: center;
    padding: 14px 8px;
    background: linear-gradient(180deg, rgba(255,255,255,0.06) 0%, rgba(255,255,255,0.02) 100%);
    border-radius: var(--radius-sm);
    border: 1px solid rgba(255,255,255,0.06);
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.04);
}

.calc-display .calc-label {
    font-size: 0.6875rem;
    color: rgba(255,255,255,0.45);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    font-weight: 600;
    margin-bottom: 6px;
}

.calc-display .calc-value {
    font-size: 1.3rem;
    font-weight: 700;
    color: #4ade80;
    font-family: 'Inter', monospace;
    text-shadow: 0 0 12px rgba(74, 222, 128, 0.4);
}

.calc-display .calc-value.cyan { color: #22d3ee; text-shadow: 0 0 12px rgba(34, 211, 238, 0.4); }
.calc-display .calc-value.green { color: #4ade80; text-shadow: 0 0 12px rgba(74, 222, 128, 0.4); }
.calc-display .calc-value.pink { color: #fb7185; text-shadow: 0 0 12px rgba(251, 113, 133, 0.4); }
.calc-display .calc-value.amber { color: #fbbf24; text-shadow: 0 0 12px rgba(251, 191, 36, 0.4); }
.calc-display .calc-value.white { color: #f1f5f9; text-shadow: 0 0 12px rgba(241, 245, 249, 0.3); }

.calc-display .calc-sub {
    font-size: 0.6875rem;
    color: rgba(255,255,255,0.3);
    margin-top: 3px;
}

/* ========================================
   FORMS
======================================== */

.form-label {
    font-weight: 600;
    font-size: 0.8125rem;
    color: var(--text-primary);
    margin-bottom: 5px;
    display: flex;
    align-items: center;
    gap: 4px;
}

.form-label i {
    color: var(--primary);
    font-size: 0.875rem;
}

.form-control,
.form-select {
    background-color: #f8fafc;
    border: 1px solid var(--border-medium);
    border-radius: var(--radius-sm);
    padding: 9px 12px;
    font-size: 0.875rem;
    color: var(--text-primary);
    transition: var(--transition-normal);
    box-shadow: var(--shadow-inset);
}

.form-control:focus,
.form-select:focus {
    background-color: #ffffff;
    border-color: var(--primary);
    box-shadow: var(--shadow-inset), 0 0 0 3px rgba(37, 99, 235, 0.12);
    outline: none;
    color: var(--text-primary);
}

.form-select {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3e%3cpath fill='none' stroke='%23475569' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M2 5l6 6 6-6'/%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    background-size: 14px 10px;
    padding-right: 2.5rem;
}

.input-group-text {
    background: linear-gradient(180deg, #f1f5f9, #e8ecf2);
    border: 1px solid var(--border-medium);
    border-right: none;
    border-radius: var(--radius-sm) 0 0 var(--radius-sm);
    padding: 9px 10px;
    color: var(--text-muted);
    font-size: 0.875rem;
    box-shadow: var(--shadow-inset);
}

.input-group > .form-control,
.input-group > .form-select {
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 14px;
}

@media (min-width: 576px) {
    .form-grid { grid-template-columns: repeat(3, 1fr); }
}

.form-grid .form-group {
    min-width: 0;
}

/* ========================================
   BUTTONS
======================================== */

.btn-calc {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    width: 100%;
    padding: 13px 24px;
    font-size: 0.9375rem;
    font-weight: 600;
    background: linear-gradient(180deg, #3b82f6 0%, #2563eb 50%, #1d4ed8 100%);
    border: none;
    border-radius: var(--radius-sm);
    color: white;
    cursor: pointer;
    transition: var(--transition-normal);
    margin-top: 16px;
    box-shadow:
        0 2px 4px rgba(37, 99, 235, 0.3),
        0 4px 12px rgba(37, 99, 235, 0.15),
        inset 0 1px 0 rgba(255,255,255,0.2);
    text-shadow: 0 1px 2px rgba(0,0,0,0.2);
    position: relative;
}

.btn-calc::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 50%;
    background: linear-gradient(180deg, rgba(255,255,255,0.12) 0%, transparent 100%);
    border-radius: var(--radius-sm) var(--radius-sm) 0 0;
    pointer-events: none;
}

.btn-calc:hover {
    background: linear-gradient(180deg, #2563eb 0%, #1d4ed8 50%, #1e40af 100%);
    transform: translateY(-1px);
    box-shadow:
        0 4px 8px rgba(37, 99, 235, 0.35),
        0 8px 20px rgba(37, 99, 235, 0.2),
        inset 0 1px 0 rgba(255,255,255,0.2);
}

.btn-calc:active {
    transform: translateY(1px);
    box-shadow:
        0 1px 2px rgba(37, 99, 235, 0.3),
        inset 0 2px 4px rgba(0,0,0,0.1);
}

.btn-primary {
    background: linear-gradient(180deg, #3b82f6, #2563eb);
    border: none;
    border-radius: var(--radius-sm);
    padding: 10px 24px;
    font-size: 0.875rem;
    font-weight: 600;
    color: white;
    transition: var(--transition-normal);
    box-shadow: 0 2px 4px rgba(37, 99, 235, 0.25), inset 0 1px 0 rgba(255,255,255,0.15);
}

.btn-primary:hover {
    background: linear-gradient(180deg, #2563eb, #1d4ed8);
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(37, 99, 235, 0.3), inset 0 1px 0 rgba(255,255,255,0.15);
}

/* ========================================
   RESULTS
======================================== */

#results {
    opacity: 0;
    transform: translateY(8px);
    transition: var(--transition-slow);
}

#results.show {
    opacity: 1;
    transform: translateY(0);
}

.result-subtitle {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 600;
}

/* ========================================
   INFO BADGE
======================================== */

.info-badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 2px 8px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-full);
    font-size: 0.6875rem;
    color: var(--text-muted);
    margin-top: 4px;
}

.info-badge i {
    color: var(--primary);
    font-size: 0.6875rem;
}

/* ========================================
   HEADERS & UTILITIES
======================================== */

h4 {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.text-primary { color: var(--primary) !important; }
.text-success { color: var(--accent-emerald) !important; }
.text-warning { color: var(--accent-amber) !important; }
.text-danger { color: var(--accent-rose) !important; }
.text-info { color: var(--accent-teal) !important; }

.alert-danger {
    background: #fef2f2;
    border: 1px solid #fecaca;
    color: #991b1b;
    border-radius: var(--radius-sm);
    padding: 8px 12px;
    font-size: 0.8125rem;
}

/* ========================================
   ANIMATIONS
======================================== */

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

.fade-in {
    animation: fadeIn 0.3s ease forwards;
}

/* ========================================
   RESPONSIVE
======================================== */

@media (max-width: 768px) {
    .container {
        margin-top: 12px;
        margin-bottom: 24px;
        padding: 0 12px;
    }
    .card-body { padding: 16px; }
    .brand-text { font-size: 0.875rem; }
    .brand-icon { font-size: 1.125rem; }
    .card-header h5,
    .card-header h4,
    .card-header h3 { font-size: 0.9375rem; }
    .calc-display .calc-value { font-size: 1.125rem; }
    .btn-calc { padding: 11px 20px; font-size: 0.875rem; }
    .navbar-nav .nav-link { padding: 8px 12px !important; }
    .form-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 400px) {
    .form-grid { grid-template-columns: 1fr; }
    .calc-display .calc-row { grid-template-columns: 1fr; }
}

/* ========================================
   SCROLLBAR & MISC
======================================== */

::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-secondary); }
::-webkit-scrollbar-thumb { background: var(--gray-300); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--gray-400); }

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

.form-check-input:checked {
    background-color: var(--primary);
    border-color: var(--primary);
}

.form-check-input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.1);
}

.table { color: var(--text-primary); }
.table th { font-weight: 600; color: var(--text-primary); }
.table td { color: var(--text-secondary); }