/* Tank Tracker - Ocean-Inspired Design System */

:root {
    --ocean-deep: #0a2540;
    --ocean-mid: #1e5a7d;
    --ocean-light: #4a9ec7;
    --coral-pink: #ff6b9d;
    --coral-orange: #ff8c42;
    --sand-light: #f4e9d8;
    --sand-dark: #d4c5aa;
    --seafoam: #88d8b0;
    --warning-yellow: #ffd93d;
    --danger-red: #ff4757;
    --text-dark: #2c3e50;
    --text-light: #ffffff;
    --shadow-sm: 0 2px 8px rgba(10, 37, 64, 0.1);
    --shadow-md: 0 4px 16px rgba(10, 37, 64, 0.15);
    --shadow-lg: 0 8px 32px rgba(10, 37, 64, 0.2);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Segoe UI', -apple-system, BlinkMacSystemFont, 'Roboto', 'Oxygen', 'Ubuntu', sans-serif;
    background: linear-gradient(135deg, var(--sand-light) 0%, var(--ocean-light) 100%);
    min-height: 100vh;
    color: var(--text-dark);
    line-height: 1.6;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

/* Header & Navigation */
header {
    background: linear-gradient(135deg, var(--ocean-deep) 0%, var(--ocean-mid) 100%);
    color: var(--text-light);
    padding: 1rem 0;
    box-shadow: var(--shadow-lg);
    position: sticky;
    top: 0;
    z-index: 1000;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--text-light);
}

.logo-gradient {
    background: linear-gradient(135deg, var(--coral-pink), var(--coral-orange));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.nav-links a {
    color: var(--text-light);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--coral-orange);
    transition: var(--transition);
}

.nav-links a:hover::after {
    width: 100%;
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 1rem;
}

/* Cards */
.card {
    background: white;
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

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

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--sand-light);
}

.card-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--ocean-deep);
}

/* Buttons */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    display: inline-block;
    text-align: center;
}

.btn-primary {
    background: linear-gradient(135deg, var(--ocean-mid), var(--ocean-light));
    color: white;
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--ocean-deep), var(--ocean-mid));
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: linear-gradient(135deg, var(--coral-pink), var(--coral-orange));
    color: white;
}

.btn-secondary:hover {
    opacity: 0.9;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--ocean-mid);
    color: var(--ocean-mid);
}

.btn-outline:hover {
    background: var(--ocean-mid);
    color: white;
}

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

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
}

/* Forms */
.form-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--ocean-deep);
}

input, select, textarea {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--sand-dark);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    transition: var(--transition);
    background: white;
}

input:focus, select:focus, textarea:focus {
    outline: none;
    border-color: var(--ocean-light);
    box-shadow: 0 0 0 3px rgba(74, 158, 199, 0.1);
}

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

/* Grid Layouts */
.grid {
    display: grid;
    gap: 2rem;
}

.grid-2 {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-3 {
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

/* Tank Cards */
.tank-card {
    background: white;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    position: relative;
}

.tank-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 6px;
    background: linear-gradient(90deg, var(--ocean-mid), var(--seafoam), var(--coral-orange));
}

.tank-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.tank-card-body {
    padding: 1.5rem;
}

.tank-name {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--ocean-deep);
    margin-bottom: 0.5rem;
}

.tank-meta {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--sand-light);
    font-size: 0.9rem;
    color: #666;
}

/* Parameter Display */
.parameters-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.parameter-item {
    background: linear-gradient(135deg, var(--sand-light), white);
    padding: 1rem;
    border-radius: var(--radius-md);
    border-left: 4px solid var(--ocean-light);
    transition: var(--transition);
}

.parameter-item:hover {
    border-left-color: var(--coral-orange);
    transform: translateX(4px);
}

.parameter-item.out-of-range {
    border-left-color: var(--danger-red);
    background: linear-gradient(135deg, #fff5f5, white);
}

.parameter-label {
    font-size: 0.85rem;
    color: #666;
    margin-bottom: 0.25rem;
}

.parameter-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--ocean-deep);
}

.parameter-unit {
    font-size: 0.9rem;
    color: #666;
    margin-left: 0.25rem;
}

.parameter-target {
    font-size: 0.75rem;
    color: #999;
    margin-top: 0.25rem;
}

/* Alerts */
.alert {
    padding: 1rem 1.5rem;
    border-radius: var(--radius-sm);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.alert-icon {
    font-size: 1.5rem;
}

.alert-critical {
    background: #fff5f5;
    border-left: 4px solid var(--danger-red);
    color: var(--danger-red);
}

.alert-high {
    background: #fff9e6;
    border-left: 4px solid var(--warning-yellow);
    color: #997700;
}

.alert-medium {
    background: #fff9e6;
    border-left: 4px solid var(--warning-yellow);
    color: #997700;
}

.alert-low {
    background: #f0f9ff;
    border-left: 4px solid var(--ocean-light);
    color: var(--ocean-mid);
}

/* Charts */
.chart-container {
    background: white;
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-md);
    margin-bottom: 2rem;
}

.chart-title {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--ocean-deep);
    margin-bottom: 1rem;
}

/* Tables */
table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

thead {
    background: linear-gradient(135deg, var(--ocean-deep), var(--ocean-mid));
    color: white;
}

th {
    padding: 1rem;
    text-align: left;
    font-weight: 600;
}

td {
    padding: 1rem;
    border-bottom: 1px solid var(--sand-light);
}

tbody tr:hover {
    background: var(--sand-light);
}

/* Dashboard Stats */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: linear-gradient(135deg, white, var(--sand-light));
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    position: relative;
    overflow: hidden;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 100px;
    height: 100px;
    background: linear-gradient(135deg, var(--ocean-light), transparent);
    border-radius: 50%;
    transform: translate(50%, -50%);
    opacity: 0.3;
}

.stat-label {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 0.5rem;
}

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

/* Modals */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(10, 37, 64, 0.8);
    z-index: 2000;
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: white;
    border-radius: var(--radius-lg);
    padding: 2rem;
    max-width: 600px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: #999;
    transition: var(--transition);
}

.modal-close:hover {
    color: var(--danger-red);
}

/* Utilities */
.text-center {
    text-align: center;
}

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

.flex {
    display: flex;
}

.flex-between {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.flex-center {
    display: flex;
    justify-content: center;
    align-items: center;
}

.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.gap-3 { gap: 1.5rem; }

/* Responsive */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .grid-2, .grid-3 {
        grid-template-columns: 1fr;
    }
    
    .parameters-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.5s ease-out;
}

@keyframes ripple {
    0% {
        transform: scale(0);
        opacity: 1;
    }
    100% {
        transform: scale(4);
        opacity: 0;
    }
}

.btn::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.5);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:active::after {
    width: 300px;
    height: 300px;
}