:root {
    /* สีประจำโรงเรียน ส้ม-น้ำเงิน */
    --color-blue: #0F4C81;
    --color-blue-dark: #0A3256;
    --color-blue-light: #EBF4FC;
    --color-orange: #FF7A00;
    --color-orange-dark: #D96800;
    --color-orange-light: #FFF2E6;
    
    --bg-primary: #F8FAFC;
    --bg-card: #FFFFFF;
    --text-main: #1E293B;
    --text-muted: #64748B;
    --border-color: #E2E8F0;
    --success: #10B981;
    --danger: #EF4444;
    --warning: #F59E0B;
    
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    
    --font-display: 'Kanit', sans-serif;
    --font-body: 'Sarabun', sans-serif;
    --transition-speed: 0.3s;
}

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

body {
    font-family: var(--font-body);
    background-color: var(--bg-primary);
    color: var(--text-main);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 500;
}

/* Header Navigation */
nav {
    background-color: #0B1E33; /* สีกรมท่าเกรดพรีเมียม */
    color: #FFFFFF;
    padding: 16px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 12px;
}

.nav-brand svg {
    color: var(--color-orange);
}

.nav-brand-text h1 {
    font-size: 16px;
    font-weight: 600;
    line-height: 1.2;
}

.nav-brand-text p {
    font-size: 11px;
    color: rgba(255, 255, 255, 0.6);
}

.btn-nav-login {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background-color: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: #FFFFFF;
    padding: 8px 16px;
    border-radius: 8px;
    text-decoration: none;
    font-family: var(--font-display);
    font-size: 13px;
    font-weight: 500;
    transition: all 0.2s;
}

.btn-nav-login:hover {
    background-color: var(--color-orange);
    border-color: var(--color-orange);
    box-shadow: 0 4px 12px rgba(255, 122, 0, 0.3);
}

/* Container & Layout */
.container {
    max-width: 1000px;
    width: 100%;
    margin: 40px auto;
    padding: 0 20px;
    flex-grow: 1;
}

.card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 32px;
    box-shadow: var(--shadow-md);
}

/* Form Elements */
.form-group {
    margin-bottom: 20px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    text-align: left;
}

.form-group label {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-main);
    display: flex;
    align-items: center;
    gap: 4px;
}

.form-group label .required {
    color: var(--danger);
}

.form-control {
    padding: 10px 14px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background-color: var(--bg-card);
    color: var(--text-main);
    font-size: 14px;
    outline: none;
    transition: border-color 0.2s, box-shadow 0.2s;
    width: 100%;
}

.form-control:focus {
    border-color: var(--color-orange);
    box-shadow: 0 0 0 3px var(--color-orange-light);
}

.form-control:disabled {
    background-color: var(--bg-primary);
    color: var(--text-muted);
    cursor: not-allowed;
}

/* Rubric Table CSS */
.table-responsive {
    overflow-x: auto;
    width: 100%;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    margin-top: 12px;
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 14px;
}

th {
    background-color: var(--color-blue-light);
    color: var(--color-blue);
    font-family: var(--font-display);
    font-weight: 500;
    padding: 10px;
    border: 1px solid var(--border-color);
    text-align: center;
}

td {
    padding: 12px 10px;
    border: 1px solid var(--border-color);
    color: var(--text-main);
    vertical-align: middle;
}

.text-center {
    text-align: center;
}

.sub-item-row td:first-child {
    padding-left: 16px;
    font-weight: 500;
}

.sub-item-row td:nth-child(2) {
    padding-left: 20px;
    color: #334155;
}

/* Custom Radio Buttons for Grid */
.radio-cell {
    text-align: center;
    cursor: pointer;
}

.radio-cell input[type="radio"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: var(--color-orange);
}

/* Upload Zones */
.upload-dropzone {
    border: 2px dashed var(--border-color);
    border-radius: 12px;
    padding: 24px;
    text-align: center;
    cursor: pointer;
    transition: border-color 0.2s, background-color 0.2s;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

.upload-dropzone:hover, .upload-dropzone.dragover {
    border-color: var(--color-orange);
    background-color: var(--color-orange-light);
}

.upload-dropzone svg {
    color: var(--text-muted);
}

.upload-dropzone:hover svg, .upload-dropzone.dragover svg {
    color: var(--color-orange);
}

.upload-dropzone p {
    font-size: 13px;
    color: var(--text-muted);
}

/* Previews */
.image-preview-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
    gap: 12px;
    margin-top: 12px;
}

.image-preview-item {
    position: relative;
    aspect-ratio: 1;
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.image-preview-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.image-preview-remove {
    position: absolute;
    top: 4px;
    right: 4px;
    background-color: rgba(239, 68, 110, 0.9);
    color: #FFFFFF;
    border: none;
    border-radius: 50%;
    width: 20px;
    height: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 10px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: 8px;
    font-weight: 500;
    font-size: 15px;
    cursor: pointer;
    transition: all 0.2s ease;
    border: 1px solid transparent;
    font-family: var(--font-display);
}

.btn-primary {
    background-color: var(--color-blue);
    color: #FFFFFF;
}
.btn-primary:hover {
    background-color: var(--color-blue-dark);
    transform: translateY(-1px);
}

.btn-outline {
    background-color: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-main);
}
.btn-outline:hover {
    background-color: #F1F5F9;
}

/* Toasts */
.toast-container {
    position: fixed;
    bottom: 24px;
    right: 24px;
    z-index: 999;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.toast {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 24px;
    border-radius: 8px;
    color: #FFFFFF;
    box-shadow: var(--shadow-lg);
    font-family: var(--font-display);
    font-size: 14px;
    min-width: 300px;
    animation: slideIn 0.3s ease forwards;
}

.toast-success { background-color: var(--success); }
.toast-danger { background-color: var(--danger); }
.toast-warning { background-color: var(--warning); }

@keyframes slideIn {
    from { transform: translateX(120%); }
    to { transform: translateX(0); }
}

footer {
    background-color: #0B1E33;
    color: rgba(255,255,255,0.5);
    text-align: center;
    padding: 20px;
    font-size: 12px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.th-practice {
    background-color: #D6E4F0 !important;
    color: var(--color-blue) !important;
}
.th-score {
    background-color: #FFE6CC !important;
    color: var(--color-orange-dark) !important;
}
.col-practice {
    background-color: #F4F9FD;
}
.col-score {
    background-color: #FFFAF5;
}