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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #1e3c72 0%, #2a5298 25%, #7e22ce 75%, #4c1d95 100%);
    background-attachment: fixed;
    min-height: 100vh;
    padding: 15px;
    color: #1d1d1f;
    line-height: 1.6;
    position: relative;
    overflow-x: hidden;
    overflow-y: auto;
}

body::before {
    content: '';
    position: fixed;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background-image: 
        radial-gradient(circle at 20% 50%, rgba(120, 119, 198, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(88, 86, 214, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 40% 20%, rgba(59, 130, 246, 0.2) 0%, transparent 50%),
        radial-gradient(circle at 90% 30%, rgba(147, 51, 234, 0.2) 0%, transparent 50%);
    animation: cloudFloat 30s ease-in-out infinite;
    z-index: 0;
}

@keyframes cloudFloat {
    0%, 100% { transform: translate(0, 0); }
    25% { transform: translate(-5%, 5%); }
    50% { transform: translate(5%, -5%); }
    75% { transform: translate(-3%, -3%); }
}

.container {
    max-width: 900px;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.95);
    -webkit-backdrop-filter: blur(20px);
    backdrop-filter: blur(20px);
    border-radius: 16px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3), 0 0 0 1px rgba(255, 255, 255, 0.2);
    overflow: visible;
    position: relative;
    z-index: 1;
    margin-bottom: 30px;
}

header {
    background: linear-gradient(135deg, rgba(30, 60, 114, 0.05) 0%, rgba(147, 51, 234, 0.05) 100%);
    color: #1d1d1f;
    padding: 20px 25px 18px;
    text-align: center;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

header h1 {
    font-size: 2em;
    margin-bottom: 4px;
    font-weight: 600;
    letter-spacing: -0.02em;
}

.subtitle {
    font-size: 1em;
    color: #86868b;
    font-weight: 400;
}

.nav-menu {
    display: flex;
    justify-content: center;
    gap: 0;
    background: rgba(249, 249, 251, 0.8);
    padding: 8px;
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
}

.nav-button {
    flex: 1;
    max-width: 200px;
    padding: 12px 24px;
    font-size: 1em;
    font-weight: 500;
    color: #6e6e73;
    background: transparent;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    font-family: inherit;
    letter-spacing: -0.01em;
}

.nav-button:hover {
    color: #1d1d1f;
    background: rgba(255, 255, 255, 0.6);
}

.nav-button.active {
    color: #007aff;
    background: rgba(255, 255, 255, 0.9);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.content-section {
    display: none;
    padding: 20px 25px 30px;
    animation: fadeIn 0.4s ease-in-out;
    overflow-y: auto;
}

.content-section.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.content-section h2 {
    color: #1d1d1f;
    font-size: 1.5em;
    margin-bottom: 16px;
    font-weight: 600;
    letter-spacing: -0.01em;
}

.content-box {
    background: rgba(255, 255, 255, 0.6);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
    padding: 16px 20px;
    margin-bottom: 12px;
    border-radius: 12px;
    border: 1px solid rgba(0, 0, 0, 0.06);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
}

.content-box:hover {
    background: rgba(255, 255, 255, 0.9);
    transform: translateY(-4px);
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.15), 0 0 24px rgba(0, 122, 255, 0.1);
    border: 1px solid rgba(0, 122, 255, 0.2);
}

.content-box h3 {
    color: #1d1d1f;
    font-size: 1.15em;
    margin-bottom: 12px;
    font-weight: 600;
    letter-spacing: -0.01em;
}

.content-box h4 {
    color: #007aff;
    font-size: 1.05em;
    margin-bottom: 8px;
    font-weight: 600;
}

.content-box p {
    line-height: 1.6;
    font-size: 1em;
    color: #1d1d1f;
    margin-bottom: 8px;
}

.content-box ul {
    margin-left: 20px;
    line-height: 1.7;
}

.content-box ul li {
    font-size: 1em;
    color: #1d1d1f;
    margin-bottom: 8px;
}

.evaluation-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 12px;
    margin-top: 12px;
}

.eval-item {
    background: rgba(255, 255, 255, 0.8);
    padding: 14px;
    border-radius: 10px;
    border-left: 3px solid #007aff;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
}

.eval-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 122, 255, 0.25), 0 0 16px rgba(0, 122, 255, 0.15);
    background: rgba(255, 255, 255, 0.95);
    border-left-width: 4px;
}

.eval-item h4 {
    margin: 0 0 6px 0;
}

.eval-item p {
    margin: 0;
    font-size: 0.95em;
    color: #6e6e73;
}

.formula {
    background: linear-gradient(135deg, rgba(0, 122, 255, 0.08) 0%, rgba(88, 86, 214, 0.08) 100%);
    padding: 14px;
    border-radius: 10px;
    text-align: center;
    margin: 10px 0;
    border: 1px solid rgba(0, 122, 255, 0.2);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
}

.formula:hover {
    background: linear-gradient(135deg, rgba(0, 122, 255, 0.15) 0%, rgba(88, 86, 214, 0.15) 100%);
    transform: scale(1.02);
    box-shadow: 0 8px 20px rgba(0, 122, 255, 0.2);
    border: 1px solid rgba(0, 122, 255, 0.4);
}

.formula p {
    font-size: 1.05em;
    margin: 0;
}

.note {
    font-size: 0.95em !important;
    color: #86868b !important;
    font-style: italic;
    margin-top: 10px;
}

.schedule-info {
    background: transparent;
    padding: 0;
}

.day {
    font-size: 1.1em;
    color: #1d1d1f;
    margin-bottom: 12px;
    font-weight: 500;
}

.schedule-item {
    display: flex;
    gap: 16px;
    background: rgba(255, 255, 255, 0.8);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
    padding: 14px 20px;
    margin-bottom: 8px;
    border-radius: 12px;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid rgba(255, 255, 255, 0.5);
    cursor: pointer;
}

.schedule-item:hover {
    background: rgba(255, 255, 255, 0.98);
    transform: scale(1.02);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
    border-color: rgba(255, 255, 255, 0.8);
}

.schedule-item.course {
    border-left: 3px solid #007aff;
}

.schedule-item.course:hover {
    box-shadow: 0 8px 24px rgba(0, 122, 255, 0.25), 0 0 32px rgba(0, 122, 255, 0.15);
}

.schedule-item.lab {
    border-left: 3px solid #5856d6;
}

.schedule-item.lab:hover {
    box-shadow: 0 8px 24px rgba(88, 86, 214, 0.25), 0 0 32px rgba(88, 86, 214, 0.15);
}

.schedule-item:last-child {
    margin-bottom: 0;
}

.time {
    flex-shrink: 0;
    font-size: 1em;
    font-weight: 500;
    color: #1d1d1f;
    min-width: 100px;
    display: flex;
    align-items: center;
    letter-spacing: -0.01em;
}

.details {
    flex: 1;
}

.details h3 {
    color: #1d1d1f;
    font-size: 1.1em;
    margin-bottom: 8px;
    font-weight: 600;
}

.details p {
    margin-bottom: 4px;
    color: #6e6e73;
    font-size: 0.95em;
}

.details strong {
    color: #1d1d1f;
    font-weight: 500;
}

.email-link {
    color: #007aff;
    text-decoration: none;
    transition: color 0.2s ease;
}

.email-link:hover {
    color: #0051d5;
    text-decoration: underline;
}

footer {
    background: linear-gradient(135deg, rgba(30, 60, 114, 0.03) 0%, rgba(147, 51, 234, 0.03) 100%);
    color: #6e6e73;
    text-align: center;
    padding: 14px;
    font-size: 0.9em;
    border-top: 1px solid rgba(0, 0, 0, 0.05);
}

/* Responsive Design */
@media (max-width: 768px) {
    body {
        padding: 10px;
    }

    header {
        padding: 18px 20px 16px;
    }

    header h1 {
        font-size: 1.4em;
    }

    .subtitle {
        font-size: 0.8em;
    }

    .nav-menu {
        padding: 6px;
        gap: 4px;
    }

    .nav-button {
        padding: 8px 12px;
        font-size: 0.75em;
        max-width: none;
    }

    .content-section {
        padding: 15px 20px;
    }

    .content-section h2 {
        font-size: 1em;
    }

    .content-box {
        padding: 12px 16px;
    }

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

    .schedule-item {
        flex-direction: column;
        gap: 10px;
        padding: 12px 16px;
    }

    .time {
        min-width: auto;
        font-size: 0.8em;
    }

    .details p {
        font-size: 0.7em;
    }
}