/* ========================================
   CSS Variables for Theming
   ======================================== */

:root {
    /* Light Mode Colors - Material Design Palette */
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --primary-light: #a5b4fc;
    --success-color: #10b981;
    --success-bg: #d1fae5;
    --warning-color: #f59e0b;
    --warning-bg: #fef3c7;
    --danger-color: #ef4444;
    --danger-bg: #fee2e2;
    --background-color: #fafafa;
    --text-color: #1f2937;
    --text-muted: #6b7280;
    --card-bg: #ffffff;
    --border-color: #e5e7eb;

    /* Material Design Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.12), 0 1px 2px rgba(0, 0, 0, 0.24);
    --shadow-md: 0 3px 6px rgba(0, 0, 0, 0.15), 0 2px 4px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 10px 20px rgba(0, 0, 0, 0.15), 0 3px 6px rgba(0, 0, 0, 0.10);
    --shadow-xl: 0 15px 25px rgba(0, 0, 0, 0.15), 0 5px 10px rgba(0, 0, 0, 0.05);

    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', sans-serif;
    --font-mono: 'SF Mono', Monaco, 'Courier New', monospace;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;

    /* Border radius - Material Design */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;

    /* Transitions - Material Design (cubic-bezier) */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark Mode Variables */
body.dark-mode {
    --primary-color: #818cf8;
    --primary-hover: #a5b4fc;
    --primary-light: #6366f1;
    --success-color: #34d399;
    --success-bg: #064e3b;
    --warning-color: #fbbf24;
    --warning-bg: #78350f;
    --danger-color: #f87171;
    --danger-bg: #7f1d1d;
    --background-color: #0f172a;
    --text-color: #f1f5f9;
    --text-muted: #94a3b8;
    --card-bg: #1e293b;
    --border-color: #334155;

    /* Dark mode shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4), 0 1px 2px rgba(0, 0, 0, 0.35);
    --shadow-md: 0 3px 6px rgba(0, 0, 0, 0.5), 0 2px 4px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 20px rgba(0, 0, 0, 0.6), 0 3px 6px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 15px 25px rgba(0, 0, 0, 0.7), 0 5px 10px rgba(0, 0, 0, 0.6);
}

/* ========================================
   Global Styles
   ======================================== */

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

body {
    font-family: var(--font-family);
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: background-color var(--transition-normal), color var(--transition-normal);
}

main {
    flex: 1;
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-lg);
}

/* ========================================
   Header
   ======================================== */

header {
    background: linear-gradient(120deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
    background-size: 200% 200%;
    animation: gradient-shift 15s ease infinite;
    color: white;
    padding: var(--spacing-md);
    box-shadow: 0 4px 20px rgba(102, 126, 234, 0.25);
    position: relative;
    overflow: hidden;
    max-width: 800px;
    margin: var(--spacing-lg) auto;
    border-radius: 50px;
}

header::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -10%;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.15) 0%, transparent 70%);
    border-radius: 50%;
    animation: float 8s ease-in-out infinite;
}

header::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -5%;
    width: 350px;
    height: 350px;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
    border-radius: 50%;
    animation: float 10s ease-in-out infinite reverse;
}

@keyframes gradient-shift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

@keyframes float {
    0%, 100% { transform: translate(0, 0); }
    33% { transform: translate(30px, -30px); }
    66% { transform: translate(-20px, 20px); }
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-lg);
}

.header-text h1 {
    font-size: 1.5rem;
    font-weight: 700;
    margin: 0;
}

.theme-toggle {
    background: rgba(255, 255, 255, 0.25);
    backdrop-filter: blur(10px);
    border: none;
    color: white;
    width: 2.5rem;
    height: 2.5rem;
    border-radius: var(--radius-full);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    transition: all var(--transition-normal);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    position: relative;
    z-index: 10;
}

.theme-toggle:hover {
    background: rgba(255, 255, 255, 0.35);
    transform: scale(1.1) rotate(15deg);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.2);
}

.theme-toggle:active {
    transform: scale(0.95) rotate(0deg);
}

/* ========================================
   Search Section & Form
   ======================================== */

#search-section {
    background: var(--card-bg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    padding: var(--spacing-2xl);
    margin-bottom: var(--spacing-xl);
    transition: all var(--transition-normal);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

body.dark-mode #search-section {
    border-color: rgba(255, 255, 255, 0.05);
}

.form-container {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.input-group label {
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--text-color);
}

.input-group input {
    padding: 1rem 1.25rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    font-size: 1rem;
    font-family: var(--font-family);
    background: var(--card-bg);
    color: var(--text-color);
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.input-group input:hover {
    border-color: var(--primary-light);
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.15);
    transform: translateY(-1px);
}

body.dark-mode .input-group input:focus {
    box-shadow: 0 0 0 4px rgba(129, 140, 248, 0.25);
}

.input-group small {
    color: var(--text-muted);
    font-size: 0.85rem;
}

.button-group {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

/* ========================================
   Buttons
   ======================================== */

.btn {
    padding: 0.875rem 2rem;
    border: none;
    border-radius: var(--radius-lg);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    font-family: var(--font-family);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-primary:active:not(:disabled) {
    transform: translateY(0);
    box-shadow: var(--shadow-md);
}

.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    box-shadow: none;
}

.btn-secondary {
    background: var(--card-bg);
    color: var(--text-color);
    border: 2px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--background-color);
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary:active {
    transform: translateY(0);
    box-shadow: var(--shadow-sm);
}

/* ========================================
   Loading Section
   ======================================== */

#loading-section {
    background: var(--card-bg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    padding: var(--spacing-2xl);
    text-align: center;
    margin-bottom: var(--spacing-xl);
    transition: all var(--transition-normal);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

body.dark-mode #loading-section {
    border-color: rgba(255, 255, 255, 0.05);
}

.loading-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-lg);
}

.spinner {
    border: 5px solid rgba(99, 102, 241, 0.1);
    border-top: 5px solid var(--primary-color);
    border-radius: 50%;
    width: 60px;
    height: 60px;
    animation: spin 0.8s cubic-bezier(0.4, 0, 0.2, 1) infinite;
    box-shadow: 0 0 20px rgba(99, 102, 241, 0.2);
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

body.dark-mode .spinner {
    border: 5px solid rgba(129, 140, 248, 0.1);
    border-top: 5px solid var(--primary-color);
    box-shadow: 0 0 20px rgba(129, 140, 248, 0.3);
}

.loading-text {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-color);
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.6; }
}

.loading-details {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* ========================================
   Error Section
   ======================================== */

#error-section {
    background: linear-gradient(135deg, var(--danger-bg) 0%, rgba(254, 226, 226, 0.7) 100%);
    border: none;
    border-left: 5px solid var(--danger-color);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    margin-bottom: var(--spacing-xl);
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-lg);
}

.error-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
    text-align: center;
}

.error-icon {
    font-size: 3.5rem;
    animation: bounce 1s ease-in-out infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.error-message {
    font-size: 1rem;
    color: var(--danger-color);
    font-weight: 500;
}

/* ========================================
   Cards
   ======================================== */

.card {
    background: var(--card-bg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    padding: var(--spacing-2xl);
    margin-bottom: var(--spacing-lg);
    transition: all var(--transition-normal);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.card:hover {
    box-shadow: var(--shadow-xl);
    transform: translateY(-2px);
}

body.dark-mode .card {
    border-color: rgba(255, 255, 255, 0.05);
}

.card h2 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--text-color);
    border-bottom: 2px solid var(--border-color);
    padding-bottom: var(--spacing-sm);
}

.card h3 {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-color);
}

/* ========================================
   Flight Info Card
   ======================================== */

.flight-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.flight-number-display {
    font-family: var(--font-mono);
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--primary-color);
}

.flight-status {
    padding: 0.625rem 1.5rem;
    border-radius: var(--radius-full);
    font-weight: 700;
    font-size: 0.9rem;
    box-shadow: var(--shadow-sm);
    letter-spacing: 0.3px;
    transition: all var(--transition-normal);
}

.flight-status:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

.flight-route {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    margin: var(--spacing-lg) 0;
    flex-wrap: wrap;
}

.airport-info {
    flex: 1;
    min-width: 150px;
}

.airport-code {
    font-family: var(--font-mono);
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-color);
}

.airport-name {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-top: var(--spacing-xs);
}

.route-arrow {
    font-size: 2rem;
    color: var(--text-muted);
}

.flight-times {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.time-info {
    padding: 1.25rem;
    background: var(--background-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
}

.time-info:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.time-label {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: var(--spacing-xs);
}

.time-value {
    font-size: 1.1rem;
    font-weight: 600;
    font-family: var(--font-mono);
    color: var(--text-color);
}

/* ========================================
   Delay Prediction Panel
   ======================================== */

.prediction-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.risk-indicator {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: 1.25rem 2.5rem;
    border-radius: var(--radius-full);
    font-size: 1.5rem;
    font-weight: 700;
    margin: var(--spacing-lg) 0;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

.risk-indicator:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-lg);
}

.risk-low {
    background: linear-gradient(135deg, #d1fae5 0%, #a7f3d0 100%);
    color: #059669;
}

.risk-medium {
    background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
    color: #d97706;
}

.risk-high {
    background: linear-gradient(135deg, #fee2e2 0%, #fecaca 100%);
    color: #dc2626;
}

.risk-icon {
    font-size: 2rem;
}

.confidence-level {
    font-size: 0.95rem;
    color: var(--text-muted);
    margin-top: var(--spacing-sm);
}

.delay-estimate {
    font-size: 1.1rem;
    color: var(--text-color);
    margin-top: var(--spacing-sm);
}

.contributing-factors {
    margin-top: var(--spacing-xl);
}

.contributing-factors h3 {
    margin-bottom: var(--spacing-md);
}

.factors-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.factors-list li {
    padding: 1rem 1.25rem;
    background: var(--background-color);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--primary-color);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
}

.factors-list li:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow-md);
    border-left-width: 6px;
}

.factor-icon {
    margin-right: var(--spacing-sm);
}

/* ========================================
   Airport Statuses
   ======================================== */

.airport-statuses {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.airport-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.airport-type-badge {
    font-size: 0.7rem;
    padding: 0.375rem 0.875rem;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    color: white;
    border-radius: var(--radius-full);
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    box-shadow: var(--shadow-sm);
}

.status-section {
    margin-bottom: var(--spacing-lg);
}

.status-section h4 {
    font-size: 1rem;
    color: var(--text-color);
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.status-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-md);
}

.status-item {
    padding: 1rem 1.25rem;
    background: var(--background-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
}

.status-item:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.status-label {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: var(--spacing-xs);
}

.status-value {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text-color);
}

.status-value.alert {
    color: var(--danger-color);
}

.status-value.warning {
    color: var(--warning-color);
}

.status-value.good {
    color: var(--success-color);
}

.delay-info {
    background: linear-gradient(135deg, var(--warning-bg) 0%, rgba(254, 243, 199, 0.7) 100%);
    padding: 1.25rem;
    border-radius: var(--radius-lg);
    border-left: 5px solid var(--warning-color);
    margin-top: var(--spacing-md);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
}

.delay-info:hover {
    box-shadow: var(--shadow-md);
    transform: translateX(4px);
}

.delay-reason {
    font-weight: 700;
    color: var(--warning-color);
    margin-bottom: var(--spacing-xs);
    font-size: 1.05rem;
}

.delay-duration {
    font-size: 0.9rem;
    color: var(--text-muted);
}

.no-delays {
    padding: 1.25rem;
    background: linear-gradient(135deg, var(--success-bg) 0%, rgba(209, 250, 229, 0.7) 100%);
    border-radius: var(--radius-lg);
    color: var(--success-color);
    text-align: center;
    font-weight: 700;
    font-size: 1.05rem;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
}

.no-delays:hover {
    box-shadow: var(--shadow-md);
    transform: scale(1.02);
}

/* ========================================
   Footer
   ======================================== */

footer {
    background: var(--card-bg);
    border-top: 1px solid var(--border-color);
    padding: var(--spacing-xl) var(--spacing-lg);
    text-align: center;
    margin-top: auto;
    transition: background-color var(--transition-normal);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
}

.footer-attribution {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: var(--spacing-xs);
}

.footer-disclaimer {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-style: italic;
}

/* ========================================
   Utility Classes
   ======================================== */

.hidden {
    display: none !important;
}

.text-center {
    text-align: center;
}

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

/* ========================================
   Responsive Design
   ======================================== */

/* Tablet */
@media (max-width: 1024px) {
    .header-text h1 {
        font-size: 1.25rem;
    }

    header {
        max-width: 90%;
        margin: var(--spacing-md) auto;
    }

    .airport-statuses {
        grid-template-columns: 1fr;
    }
}

/* Mobile */
@media (max-width: 768px) {
    main {
        padding: var(--spacing-md);
    }

    header {
        padding: var(--spacing-md);
        margin: var(--spacing-md) var(--spacing-sm);
        border-radius: 35px;
    }

    .header-content {
        flex-direction: row;
        gap: var(--spacing-md);
    }

    .header-text h1 {
        font-size: 1.25rem;
    }

    .theme-toggle {
        width: 2.5rem;
        height: 2.5rem;
        font-size: 1.25rem;
    }

    #search-section {
        padding: var(--spacing-lg);
    }

    .button-group {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }

    .flight-route {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .route-arrow {
        transform: rotate(90deg);
    }

    .airport-code {
        font-size: 1.5rem;
    }

    .flight-times {
        grid-template-columns: 1fr;
    }

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

    .card {
        padding: var(--spacing-lg);
    }
}

/* Small mobile */
@media (max-width: 480px) {
    .header-text h1 {
        font-size: 1rem;
    }

    header {
        border-radius: 25px;
    }

    .flight-number-display {
        font-size: 1.4rem;
    }

    .risk-indicator {
        font-size: 1.2rem;
        padding: var(--spacing-md) var(--spacing-lg);
    }
}