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

:root {
    --color-white: #FFFFFF;
    --color-primary: #59a5d8;
    --color-dark: #003459;
    --color-accent: #6d1a36;
    --color-darkest: #00171f;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--color-darkest);
    background: linear-gradient(135deg, #f5f7fa 0%, #e8eef3 100%);
    min-height: 100vh;
}

.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

header {
    background: linear-gradient(135deg, var(--color-dark) 0%, var(--color-primary) 100%);
    color: var(--color-white);
    padding: 30px 0;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}
.logo { display: flex; align-items: center; gap: 15px; margin-bottom: 10px; }
.logo h1 { font-size: 2.5em; font-weight: 700; }
.tagline { font-size: 1.1em; opacity: 0.95; margin-left: 65px; }

main { padding: 40px 20px; }

.form-section {
    background: var(--color-white);
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.1);
    margin-bottom: 50px;
}
.form-section h2 { color: var(--color-dark); margin-bottom: 25px; font-size: 1.8em; }
.form-group { margin-bottom: 20px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }

label { display: block; margin-bottom: 8px; color: var(--color-dark); font-weight: 600; }

input[type="text"], input[type="password"], input[type="file"], textarea, select {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 1em;
    font-family: inherit;
    transition: all 0.3s ease;
}
input[type="text"]:focus, input[type="password"]:focus, textarea:focus, select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(89, 165, 216, 0.1);
}
textarea { resize: vertical; min-height: 100px; }
input[type="checkbox"] { width: 18px; height: 18px; margin-right: 8px; cursor: pointer; }
small { display: block; margin-top: 5px; color: #666; font-size: 0.9em; }

.btn-primary, .btn-secondary {
    padding: 14px 30px;
    border: none;
    border-radius: 8px;
    font-size: 1em;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
}
.btn-primary { background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-dark) 100%); color: var(--color-white); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(89, 165, 216, 0.4); }
.btn-secondary { background: var(--color-accent); color: var(--color-white); }
.btn-secondary:hover { background: #8a2244; transform: translateY(-2px); }

.notation-section {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 10px;
    margin: 20px 0;
    border-left: 4px solid var(--color-primary);
}
.notation-preview { margin-top: 15px; padding: 20px; background: white; border-radius: 8px; min-height: 100px; }

.alert { padding: 15px 20px; border-radius: 8px; margin-bottom: 25px; font-weight: 500; }
.alert.success { background: #d4edda; color: #155724; border-left: 4px solid #28a745; }
.alert.error { background: #f8d7da; color: #721c24; border-left: 4px solid #dc3545; }

.exercises-section { margin-top: 50px; }
.section-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 30px; }
.section-header h2 { color: var(--color-dark); font-size: 2em; }
.exercises-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(350px, 1fr)); gap: 25px; }

.exercise-card {
    background: var(--color-white);
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    border-top: 4px solid var(--color-primary);
}
.exercise-card:hover { transform: translateY(-5px); box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15); }
.exercise-card h3 { color: var(--color-dark); margin-bottom: 10px; font-size: 1.4em; }
.exercise-card .author { color: var(--color-accent); font-style: italic; margin-bottom: 12px; font-size: 0.95em; }
.exercise-card .description { color: #333; margin-bottom: 15px; line-height: 1.7; }
.exercise-card .timestamp { color: #999; font-size: 0.85em; margin-top: 15px; padding-top: 15px; border-top: 1px solid #eee; }

.exercise-image { width: 100%; max-height: 300px; object-fit: cover; border-radius: 8px; margin: 15px 0; }
.notation-display { margin: 15px 0; padding: 15px; background: #fafafa; border-radius: 8px; overflow-x: auto; }
.empty-state { text-align: center; padding: 60px 20px; background: var(--color-white); border-radius: 12px; color: #666; }

footer { background: var(--color-darkest); color: var(--color-white); padding: 25px 0; text-align: center; margin-top: 60px; }
footer p { margin-bottom: 10px; }
.admin-link { color: var(--color-primary); text-decoration: none; font-size: 0.9em; }
.admin-link:hover { text-decoration: underline; }

@media (max-width: 768px) {
    .logo h1 { font-size: 2em; }
    .form-section { padding: 25px; }
    .form-row { grid-template-columns: 1fr; }
    .exercises-grid { grid-template-columns: 1fr; }
    .section-header { flex-direction: column; align-items: flex-start; gap: 15px; }
}
/* Filterleiste */
.filter-bar { display: flex; flex-wrap: wrap; gap: 12px; align-items: flex-end;
    background: #f5f9fc; border: 1px solid #dce8f1; border-radius: 10px;
    padding: 14px; margin: 18px 0; }
.filter-item { display: flex; flex-direction: column; gap: 4px; }
.filter-item label { font-size: 13px; color: #555; }
.filter-item select { padding: 7px 10px; border: 1px solid #ccd6de; border-radius: 6px; background: #fff; }
.filter-actions { flex-direction: row; align-items: center; gap: 12px; }
.filter-reset { font-size: 14px; color: #59a5d8; }
.filter-count { width: 100%; font-size: 13px; color: #777; }
.badge { display: inline-block; padding: 2px 10px; border-radius: 12px;
    background: #e3f1fa; color: #2b6a94; font-size: 13px; margin-right: 6px; }
.stars { color: #e5a400; letter-spacing: 1px; }
/* Syntax-Hilfe unter der Noteneingabe */
.syntax-help { margin-top: 8px; border: 1px solid #dce8f1; border-radius: 8px; background: #f5f9fc; padding: 8px 12px; }
.syntax-help summary { cursor: pointer; color: #2b6a94; font-size: 14px; }
.syntax-help table { width: 100%; border-collapse: collapse; margin-top: 10px; font-size: 13px; }
.syntax-help th, .syntax-help td { padding: 6px 8px; border-bottom: 1px solid #e0e8ee; text-align: left; vertical-align: top; }
.syntax-help code { background: #fff; border: 1px solid #dde5ec; border-radius: 4px; padding: 0 4px; }
/* Ein-/ausklappbare Formular-Überschrift */
.form-toggle-heading { margin: 0 0 15px; }
.form-toggle {
    display: flex; justify-content: space-between; align-items: center;
    width: 100%; padding: 12px 16px; cursor: pointer;
    font: inherit; font-size: inherit; font-weight: inherit; color: inherit; text-align: left;
    background: #f5f9fc; border: 1px solid #dce8f1; border-radius: 10px;
}
.form-toggle:hover { background: #e9f3fa; }
.form-toggle:focus-visible { outline: 2px solid #59a5d8; outline-offset: 2px; }
.form-toggle .chevron { transition: transform 0.2s; margin-left: 12px; }
.form-toggle:not(.open) .chevron { transform: rotate(-90deg); }