:root {
    --primary-color: #4a90e2;
    --secondary-color: #50e3c2;
    --background-color: #f4f7f6;
    --text-color: #333;
    --light-text-color: #fff;
    --card-bg-color: #ffffff;
    --border-color: #e0e0e0;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --danger-color: #d0021b;

    --subject-color-1: #4a90e2; /* 自然 */
    --subject-color-2: #f5a623; /* 社會 */
    --subject-color-3: #7ed321; /* 健康 */
    --subject-color-4: #bd10e0; /* 彈性 */
    --subject-color-default: #9b9b9b;
    
    --card-color-default: var(--card-bg-color);
    --card-color-1: #81D4FA; /* light blue */
    --card-color-2: #A5D6A7; /* light green */
    --card-color-3: #FFCC80; /* light orange */
    --card-color-4: #CE93D8; /* light purple */
    --card-color-5: #EF9A9A; /* light red */
}

body {
    font-family: 'Noto Sans TC', sans-serif;
    margin: 0;
    background-color: var(--background-color);
    color: var(--text-color);
    overscroll-behavior: none;
}

header {
    background-color: var(--primary-color);
    color: var(--light-text-color);
    padding: 1rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 4px var(--shadow-color);
}

header h1 {
    margin: 0;
    font-size: 1.25rem;
    flex-grow: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.header-actions {
    flex-shrink: 0;
}

.header-actions button {
    margin-left: 0.5rem;
}

main {
    padding: 1.5rem;
}

h2, h3 {
    color: var(--primary-color);
}

.hidden {
    display: none !important;
}

/* 列表容器 */
.list-container {
    display: grid;
    gap: 1rem;
}

/* 班級卡片 */
.class-card {
    background-color: var(--card-color-default);
    color: var(--text-color);
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 2px 5px var(--shadow-color);
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s, background-color 0.2s;
    position: relative;
    border-left: 5px solid var(--primary-color);
}

.class-card[data-color="default"] {
    border-left-color: var(--primary-color);
}
.class-card[data-color="1"] { background-color: var(--card-color-1); border-left: none; }
.class-card[data-color="2"] { background-color: var(--card-color-2); border-left: none; }
.class-card[data-color="3"] { background-color: var(--card-color-3); border-left: none; }
.class-card[data-color="4"] { background-color: var(--card-color-4); border-left: none; }
.class-card[data-color="5"] { background-color: var(--card-color-5); border-left: none; }

.class-card.light-text,
.class-card.light-text h3,
.class-card.light-text .summary,
.class-card.light-text .card-actions button {
    color: var(--light-text-color);
}

.class-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 4px 8px var(--shadow-color);
}

.class-card h3 {
    margin: 0 0 0.5rem;
    font-size: 1.5rem;
    color: inherit;
}

.class-card .summary {
    font-size: 0.9rem;
    color: inherit;
    opacity: 0.8;
    min-height: 1.2em;
}

.card-actions {
    position: absolute;
    top: 1rem;
    right: 1rem;
}

.card-actions button {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.2rem;
    padding: 0.25rem;
    color: #999;
}
.card-actions button:hover {
    color: var(--primary-color);
}

.class-card.light-text .card-actions button:hover {
    opacity: 0.8;
}

/* FAB 按鈕 */
.fab {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background-color: var(--secondary-color);
    color: var(--light-text-color);
    font-size: 2rem;
    border: none;
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s, transform 0.2s;
}
.fab:hover {
    background-color: #48c9b0;
    transform: scale(1.05);
}

/* 詳細視圖 */
#class-detail-view .view-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

#class-detail-view h2 {
    margin: 0;
}

#back-to-list-btn {
    font-size: 1.5rem;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    line-height: 1;
}

/* 表單 */
#record-form-container {
    background: var(--card-bg-color);
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 2rem;
    box-shadow: 0 2px 5px var(--shadow-color);
}

form {
    display: grid;
    gap: 1rem;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    margin-bottom: 0.5rem;
    font-weight: 500;
}

input[type="text"],
input[type="date"],
select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 1rem;
    box-sizing: border-box;
}

.checkbox-group {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.checkbox-group label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.color-selector {
    display: flex;
    gap: 0.75rem;
    align-items: center;
    margin-top: 0.5rem;
}

.color-dot {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    cursor: pointer;
    border: 2px solid transparent;
    transition: transform 0.2s, border-color 0.2s;
}

.color-dot:hover {
    transform: scale(1.1);
}

.color-dot.selected {
    border-color: var(--primary-color);
}

.color-dot[data-color="default"] { background-color: var(--card-bg-color); border-color: #ccc; }
.color-dot[data-color="1"] { background-color: var(--card-color-1); }
.color-dot[data-color="2"] { background-color: var(--card-color-2); }
.color-dot[data-color="3"] { background-color: var(--card-color-3); }
.color-dot[data-color="4"] { background-color: var(--card-color-4); }
.color-dot[data-color="5"] { background-color: var(--card-color-5); }

button {
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    background-color: var(--primary-color);
    color: var(--light-text-color);
    font-weight: 500;
    transition: background-color 0.2s;
}
button:hover {
    opacity: 0.9;
}

button.secondary-btn {
    background-color: transparent;
    border: 1px solid var(--light-text-color);
    color: var(--light-text-color);
}

button.danger-btn {
    background-color: var(--danger-color);
}

/* 進度歷史 */
.history-header {
    display: flex;
    align-items: center;
    margin-bottom: 1rem;
}

.record-card {
    background-color: var(--card-bg-color);
    border-radius: 8px;
    padding: 0 1.5rem;
    box-shadow: 0 2px 5px var(--shadow-color);
    position: relative;
    border-left: 5px solid var(--primary-color);
    overflow: hidden;
    transition: padding 0.3s ease;
}

.record-card.expanded {
    padding-top: 1.5rem;
    padding-bottom: 1.5rem;
}

.record-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 0;
    cursor: pointer;
    padding: 1rem 0;
}

.record-card.expanded .record-header {
    padding-top: 0;
    padding-bottom: 1rem;
    cursor: default;
}

.record-header h4 {
    margin: 0;
    font-size: 1.2rem;
    font-weight: 700;
}

.record-header .card-actions {
    cursor: default;
}

.record-header .date {
    font-size: 0.9rem;
    color: #666;
    font-weight: 500;
}

.record-body {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height 0.4s ease-out, opacity 0.3s ease-in-out;
}

.record-card.expanded .record-body {
    max-height: 500px; /* A reasonable max height */
    opacity: 1;
}

.record-item {
    margin-bottom: 0.75rem;
}
.record-item strong {
    color: var(--primary-color);
}

/* 彈出視窗 */
#modal-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.modal-content {
    background-color: var(--card-bg-color);
    padding: 2rem;
    border-radius: 8px;
    width: 90%;
    max-width: 500px;
    position: relative;
    box-shadow: 0 5px 15px rgba(0,0,0,0.3);
}

.modal-close-btn {
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: #999;
    cursor: pointer;
}

#modal-form button {
    margin-top: 1rem;
    width: 100%;
}