/* ============ БАЗОВЫЕ СТИЛИ ============ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --ice-blue: #a8d8ea;
    --deep-blue: #1a3a5c;
    --glacier: #e0f0f8;
    --accent: #4a90b8;
    --white: #ffffff;
    --dark: #1a1a2e;
    --light-gray: #f5f7fa;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    --radius: 12px;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.7;
    color: #333;
    background: var(--light-gray);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ============ НАВИГАЦИЯ ============ */
header {
    background: var(--deep-blue);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
    flex-wrap: wrap;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--ice-blue);
    letter-spacing: 1px;
}

nav ul {
    display: flex;
    list-style: none;
    gap: 0.5rem;
    flex-wrap: wrap;
}

nav ul li a {
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 25px;
    transition: all 0.3s ease;
    font-size: 0.95rem;
    display: block;
}

nav ul li a:hover {
    background: rgba(255, 255, 255, 0.15);
    color: var(--white);
}

nav ul li a.active {
    background: var(--ice-blue);
    color: var(--deep-blue);
    font-weight: 600;
}

/* ============ MAIN ============ */
main {
    flex: 1;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    width: 100%;
}

.page-title {
    font-size: 2.2rem;
    color: var(--deep-blue);
    margin-bottom: 1.5rem;
    text-align: center;
}

/* ============ HERO (ГЛАВНАЯ) ============ */
.hero {
    background: linear-gradient(135deg, var(--deep-blue), #2d5f8a, var(--accent));
    color: var(--white);
    padding: 4rem 2rem;
    border-radius: var(--radius);
    text-align: center;
    margin-bottom: 2rem;
}

.hero h1 {
    font-size: 2.8rem;
    margin-bottom: 1rem;
    letter-spacing: 2px;
}

.hero p {
    font-size: 1.2rem;
    max-width: 700px;
    margin: 0 auto 2rem;
    opacity: 0.9;
}

.btn {
    display: inline-block;
    background: var(--ice-blue);
    color: var(--deep-blue);
    padding: 0.8rem 2rem;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn:hover {
    background: var(--white);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

/* ============ ФАКТЫ ============ */
.facts h2, .intro h2 {
    font-size: 1.8rem;
    color: var(--deep-blue);
    margin-bottom: 1.5rem;
    text-align: center;
}

.facts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.fact-card {
    background: var(--white);
    padding: 1.5rem;
    border-radius: var(--radius);
    text-align: center;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease;
}

.fact-card:hover {
    transform: translateY(-5px);
}

.fact-icon {
    font-size: 2.5rem;
    display: block;
    margin-bottom: 0.5rem;
}

.fact-card h3 {
    font-size: 1.6rem;
    color: var(--deep-blue);
    margin-bottom: 0.3rem;
}

.fact-card p {
    color: #666;
    font-size: 0.95rem;
}

/* ============ ИНТРО ============ */
.intro {
    background: var(--white);
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.intro p {
    margin-bottom: 1rem;
    font-size: 1.05rem;
}

/* ============ ТИПЫ ЛЬДА ============ */
.type-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.type-card {
    background: var(--white);
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border-top: 4px solid var(--ice-blue);
}

.type-icon {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.type-card h2 {
    color: var(--deep-blue);
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

.type-card p {
    color: #555;
    font-size: 0.95rem;
}

/* ============ ТАБЛИЦА ============ */
.comparison table {
    width: 100%;
    border-collapse: collapse;
    background: var(--white);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
}

.comparison th {
    background: var(--deep-blue);
    color: var(--white);
    padding: 1rem;
    text-align: left;
}

.comparison td {
    padding: 0.8rem 1rem;
    border-bottom: 1px solid #eee;
}

.comparison tr:hover td {
    background: var(--glacier);
}

.comparison h2 {
    color: var(--deep-blue);
    margin-bottom: 1rem;
    text-align: center;
    font-size: 1.6rem;
}

/* ============ ШЕЛЬФОВЫЕ ЛЕДНИКИ ============ */
.lead {
    font-size: 1.15rem;
    color: #555;
    text-align: center;
    max-width: 800px;
    margin: 0 auto 2rem;
}

.shelf-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.shelf-card {
    background: var(--white);
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border-left: 5px solid var(--accent);
}

.shelf-card h2 {
    color: var(--deep-blue);
    margin-bottom: 0.8rem;
}

.shelf-card p {
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
    color: #444;
}

.warning {
    background: #fff3e0;
    border: 2px solid #ff9800;
    padding: 1.5rem;
    border-radius: var(--radius);
}

.warning h2 {
    color: #e65100;
    margin-bottom: 1rem;
}

.warning p {
    margin-bottom: 0.8rem;
}

/* ============ ИССЛЕДОВАНИЯ ============ */
.research-intro {
    background: var(--glacier);
    padding: 1.5rem;
    border-radius: var(--radius);
    margin-bottom: 2rem;
}

.research-intro h2 {
    color: var(--deep-blue);
    margin-bottom: 0.8rem;
}

.method-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.method-card {
    background: var(--white);
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.method-card h3 {
    color: var(--deep-blue);
    margin-bottom: 0.5rem;
}

.method-card p {
    font-size: 0.92rem;
    color: #555;
    margin-bottom: 0.5rem;
}

.stations {
    background: var(--white);
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
}

.stations h2 {
    color: var(--deep-blue);
    margin-bottom: 1rem;
}

.stations ul {
    list-style: none;
    padding: 0;
}

.stations li {
    padding: 0.5rem 0;
    border-bottom: 1px solid #eee;
}

.discovery-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.discovery {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: var(--white);
    padding: 1rem 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.discovery .year {
    background: var(--deep-blue);
    color: var(--white);
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-weight: bold;
    font-size: 0.85rem;
    white-space: nowrap;
}

/* ============ ЭКОЛОГИЯ ============ */
.intro-text p {
    font-size: 1.1rem;
    text-align: center;
    max-width: 700px;
    margin: 0 auto 2rem;
    color: #555;
}

.problems {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.problem-card {
    background: var(--white);
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border-bottom: 4px solid #e74c3c;
}

.problem-card h2 {
    color: #c0392b;
    font-size: 1.2rem;
    margin-bottom: 0.8rem;
}

.problem-card p {
    font-size: 0.95rem;
    color: #555;
}

.stat {
    display: inline-block;
    background: #fde8e8;
    color: #c0392b;
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-weight: bold;
    font-size: 0.9rem;
    margin-top: 0.8rem;
}

.future h2 {
    color: var(--deep-blue);
    text-align: center;
    margin-bottom: 1.5rem;
    font-size: 1.8rem;
}

.scenarios {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.scenario {
    padding: 1.5rem;
    border-radius: var(--radius);
    color: var(--white);
}

.scenario:nth-child(1) {
    background: linear-gradient(135deg, #27ae60, #2ecc71);
}

.scenario:nth-child(2) {
    background: linear-gradient(135deg, #f39c12, #e67e22);
}

.scenario:nth-child(3) {
    background: linear-gradient(135deg, #c0392b, #e74c3c);
}

.scenario h3 {
    margin-bottom: 0.8rem;
    font-size: 1.1rem;
}

.scenario p {
    font-size: 0.92rem;
    opacity: 0.95;
}

.what-can-we-do {
    background: var(--white);
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.what-can-we-do h2 {
    color: var(--deep-blue);
    margin-bottom: 1rem;
}

.what-can-we-do ul {
    list-style: none;
    padding: 0;
}

.what-can-we-do li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
}

.what-can-we-do li::before {
    content: "✅";
    position: absolute;
    left: 0;
}

/* ============ FOOTER ============ */
footer {
    background: var(--deep-blue);
    color: rgba(255, 255, 255, 0.8);
    text-align: center;
    padding: 1.5rem;
    margin-top: auto;
}

footer p {
    font-size: 0.9rem;
}

/* ============ АДАПТИВНОСТЬ ============ */
@media (max-width: 768px) {
    nav {
        flex-direction: column;
        gap: 0.8rem;
        padding: 1rem;
    }
    
    nav ul {
        justify-content: center;
    }
    
    nav ul li a {
        padding: 0.4rem 0.7rem;
        font-size: 0.85rem;
    }
    
    main {
        padding: 1rem;
    }
    
    .hero {
        padding: 2rem 1rem;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .page-title {
        font-size: 1.8rem;
    }
    
    .facts-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .shelf-list {
        grid-template-columns: 1fr;
    }
    
    .type-grid {
        grid-template-columns: 1fr;
    }
    
    .discovery {
        flex-direction: column;
        align-items: flex-start;
    }
}

@media (max-width: 480px) {
    .facts-grid {
        grid-template-columns: 1fr;
    }
    
    nav ul {
        flex-direction: column;
        align-items: center;
        width: 100%;
    }
    
    nav ul li {
        width: 100%;
        text-align: center;
    }
    
    .comparison table {
        font-size: 0.8rem;
    }
    
    .comparison th, .comparison td {
        padding: 0.5rem;
    }
}