/* ===== PLMunTrack Professional Theme ===== */
:root {
    --primary: #173b7a;
    --primary-dark: #102b59;
    --accent: #3478f6;
    --background: #f3f6fb;
    --surface: #ffffff;
    --text: #172b4d;
    --muted: #687891;
    --border: #dce4ef;
    --success: #15803d;
}

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

body {
    font-family: "Segoe UI", Arial, sans-serif;
    background: var(--background);
    color: var(--text);
    min-height: 100vh;
    line-height: 1.6;
}

/* Header */
header {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary));
    color: white;
    text-align: center;
    padding: 36px 20px 40px;
    box-shadow: 0 4px 18px rgba(16, 43, 89, 0.15);
}

header h1 {
    font-size: clamp(30px, 4vw, 42px);
    font-weight: 750;
    letter-spacing: -1px;
    margin-bottom: 8px;
}

header p {
    color: #dbeafe;
    font-size: 14px;
}

/* Main layout */
main {
    display: flex;
    justify-content: center;
    align-items: flex-start;
    padding: 48px 20px;
}

.welcome-card {
    background: var(--surface);
    width: 100%;
    max-width: 850px;
    padding: 38px;
    border: 1px solid #e8edf5;
    border-radius: 20px;
    box-shadow: 0 12px 35px rgba(25, 48, 85, 0.08);
}

.welcome-card > h2 {
    color: var(--primary);
    font-size: 27px;
    margin-bottom: 8px;
    text-align: center;
}

.welcome-card > p {
    color: var(--muted);
    text-align: center;
    margin-bottom: 22px;
}

/* Navigation buttons */
.menu {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
    margin: 28px 0 32px;
}

button {
    font-family: inherit;
    background: var(--accent);
    color: white;
    border: none;
    padding: 13px 18px;
    min-height: 48px;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 650;
    cursor: pointer;
    transition: background 0.2s ease, transform 0.2s ease,
                box-shadow 0.2s ease;
}

button:hover {
    background: #245fd0;
    box-shadow: 0 5px 12px rgba(52, 120, 246, 0.2);
    transform: translateY(-1px);
}

button:focus-visible,
input:focus-visible {
    outline: 3px solid #93c5fd;
    outline-offset: 2px;
}

/* Registration section */
#studentForm {
    margin-top: 24px;
    padding: 28px;
    background: #f9fbff;
    border: 1px solid var(--border);
    border-radius: 16px;
}

#studentForm[hidden] {
    display: none;
}

#studentForm h2 {
    color: var(--primary);
    font-size: 22px;
    margin-bottom: 22px;
    padding-bottom: 14px;
    border-bottom: 1px solid var(--border);
}

#registrationForm {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px 20px;
}

#registrationForm label {
    display: block;
    font-size: 13px;
    font-weight: 650;
    color: #334766;
    margin-top: 6px;
}

#registrationForm input {
    width: 100%;
    min-width: 0;
    padding: 12px 13px;
    border: 1px solid #cbd6e5;
    border-radius: 9px;
    background: white;
    color: var(--text);
    font: inherit;
    font-size: 14px;
    transition: border-color 0.2s, box-shadow 0.2s;
}

#registrationForm input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(52, 120, 246, 0.12);
    outline: none;
}

#registrationForm input::placeholder {
    color: #94a3b8;
}

#registrationForm button {
    grid-column: 1 / -1;
    margin-top: 14px;
}

/* Status message */
#message {
    color: var(--muted);
    font-size: 14px;
    text-align: center;
    margin-top: 20px;
    overflow-wrap: anywhere;
}

/* Footer */
footer {
    text-align: center;
    padding: 18px 20px 28px;
    color: var(--muted);
    font-size: 12px;
}

/* Mobile layout */
@media (max-width: 600px) {
    header {
        padding: 28px 16px 32px;
    }

    main {
        padding: 25px 14px;
    }

    .welcome-card {
        padding: 24px 18px;
        border-radius: 15px;
    }

    .welcome-card > h2 {
        font-size: 23px;
    }

    .menu {
        grid-template-columns: 1fr;
        gap: 10px;
        margin: 22px 0;
    }

    #studentForm {
        padding: 20px 15px;
    }

    #registrationForm {
        grid-template-columns: 1fr;
        gap: 8px;
    }
}