:root {
    --bg: #f2f6fb;
    --card: #ffffff;
    --text: #222831;
    --muted: #556577;
    --primary: #2f80ed;
    --primary-dark: #1f6fe0;
    --border: rgba(34, 40, 49, 0.08);
    --radius: 16px;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: "Segoe UI", "Helvetica Neue", Arial, sans-serif;
    color: var(--text);
    background: linear-gradient(180deg, #edf2fb 0%, #f7fbff 100%);
    line-height: 1.6;
}

header {
    background: #ffffffee;
    padding: 20px 24px;
    box-shadow: 0 2px 20px rgba(15, 23, 42, 0.06);
    position: sticky;
    top: 0;
    z-index: 10;
}

header h1 {
    margin: 0 0 12px;
    font-size: 1.8rem;
    letter-spacing: 0.02em;
}

nav ul {
    display: flex;
    gap: 18px;
    padding: 0;
    margin: 0;
    list-style: none;
    flex-wrap: wrap;
}

nav a {
    color: var(--muted);
    text-decoration: none;
    font-weight: 600;
}

nav a:hover {
    color: var(--text);
}

main {
    max-width: 960px;
    margin: 0 auto;
    padding: 30px 24px 60px;
}

section {
    background: rgba(255, 255, 255, 0.92);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    margin-bottom: 24px;
}

section h2 {
    margin-top: 0;
    margin-bottom: 16px;
    font-size: 1.4rem;
    color: #1f2937;
}

p {
    color: var(--muted);
    margin: 0;
}

#container {
    width: 100%;
    min-height: 420px;
    border-radius: 16px;
    overflow: hidden;
    border: 1px solid var(--border);
    background: #e7f0ff;
    margin: 20px 0;
}

.info-panel {
    position: relative;
    background: var(--card);
    padding: 18px 20px;
    border-radius: 16px;
    box-shadow: 0 10px 28px rgba(15, 23, 42, 0.08);
    margin-bottom: 30px;
}

.info-panel h3 {
    margin: 0 0 8px;
    font-size: 1.05rem;
    color: #111827;
}

.info-panel p {
    margin: 0;
    color: var(--muted);
}

.info-panel button,
button[type="submit"] {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-top: 16px;
    padding: 12px 18px;
    border: none;
    background: var(--primary);
    color: white;
    border-radius: 10px;
    cursor: pointer;
    transition: background 0.2s ease;
    font-weight: 700;
}

.info-panel button:hover,
button[type="submit"]:hover {
    background: var(--primary-dark);
}

form {
    display: grid;
    gap: 16px;
}

label {
    display: block;
    font-weight: 600;
    margin-bottom: 8px;
}

input[type="text"], textarea {
    width: 100%;
    padding: 14px 16px;
    border: 1px solid var(--border);
    border-radius: 12px;
    font-size: 1rem;
    outline: none;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

input[type="text"]:focus,
textarea:focus {
    border-color: rgba(47, 128, 237, 0.5);
    box-shadow: 0 0 0 4px rgba(47, 128, 237, 0.12);
}

textarea {
    min-height: 140px;
    resize: vertical;
}

footer {
    text-align: center;
    padding: 18px 24px 28px;
    color: var(--muted);
    font-size: 0.95rem;
}

@media (max-width: 720px) {
    nav ul {
        flex-direction: column;
        gap: 10px;
    }

    main {
        padding: 20px 16px 40px;
    }
}