/* Color Theme Definitions */
:root {
    --bg-main: #FEFEFE;
    --bg-sidebar: #F6F3E9;
    --border-color: #C3C3C3;
    --accent-color: #B4B4B4;
    --text-main: #2b2b2b;
}

/* Core Layout */
body {
    margin: 0;
    padding: 0;
    font-family: 'Inter', -apple-system, sans-serif;
    background-color: var(--bg-main);
    color: var(--text-main);
}

.saber-layout {
    display: flex;
    height: 100vh;
    background-color: var(--bg-main);
}

/* Sidebar Styling */
.saber-sidebar {
    width: 250px;
    background-color: var(--bg-sidebar);
    color: var(--text-main);
    display: flex;
    flex-direction: column;
    border-right: 1px solid var(--border-color);
}

.sidebar-header {
    padding: 16px 20px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: flex-start;
    align-items: center;
}

.sidebar-logo {
    max-width: 90px;
    height: auto;
    display: block;
}

.sidebar-nav {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    flex: 1;
}

.nav-item {
    padding: 15px 20px;
    cursor: pointer;
    transition: background 0.2s;
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-main);
}

.nav-item:hover, .nav-item.active {
    background-color: var(--accent-color);
    color: var(--bg-main);
    border-left: 4px solid var(--text-main);
}

#nav-logout {
    margin-top: auto;
    border-top: 1px solid var(--border-color);
}

/* Main Content Styling */
.saber-content {
    flex: 1;
    padding: 40px;
    overflow-y: auto;
    background-color: var(--bg-main);
}

/* Typography & Layout spacing */
h1 { color: var(--text-main); margin-top: 0; }
h2 { color: var(--text-main); margin-top: 30px; border-bottom: 1px solid var(--border-color); padding-bottom: 10px; }

/* Grid Layout for Class Cards */
.saber-card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
    margin-top: 20px;
}

.class-banners-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
    margin-top: 20px;
}

/* Rounded Class Cards */
.saber-class-card {
    background: var(--bg-sidebar);
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.03);
    border: 1px solid var(--border-color);
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    flex-direction: column;
    justify-content: center;
    min-height: 120px;
}

.saber-class-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.08);
    border-color: var(--accent-color);
}

.saber-class-card h3 { margin: 0 0 8px 0; color: var(--text-main); text-align: center; }
.saber-class-card p { margin: 0; color: var(--accent-color); font-size: 0.9em; text-align: center; }

.card-top-row {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 8px;
}
.card-top-row h3 { text-align: left; margin: 0; }
.saber-class-card:not(.create-card) p { text-align: left; }

.icon-btn-delete {
    background: none;
    border: none;
    color: var(--accent-color);
    padding: 4px 6px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 13px;
    line-height: 1;
    transition: color 0.2s, background-color 0.2s;
    flex-shrink: 0;
}
.icon-btn-delete:hover { color: #b93a3a; background-color: rgba(185, 58, 58, 0.08); }

/* Create Card Modifier */
.saber-class-card.create-card {
    border: none;
    background-color: transparent;
    align-items: center;
    justify-content: center;
    box-shadow: none;
    gap: 12px;
}

.saber-class-card.create-card:hover {
    transform: none;
    box-shadow: none;
    border-color: transparent;
}

.create-icon-btn {
    width: 80px;
    height: 80px;
    border-radius: 16px;
    background-color: var(--bg-sidebar);
    border: 2px dashed var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    font-weight: 300;
    color: var(--accent-color);
    cursor: pointer;
    transition: transform 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.saber-class-card.create-card:hover .create-icon-btn {
    transform: scale(1.05);
    border-color: var(--text-main);
    color: var(--text-main);
}

.saber-class-card.create-card:active .create-icon-btn {
    transform: scale(0.95);
}

.saber-class-card.create-card h3 {
    color: var(--accent-color);
    font-weight: 500;
    margin: 0;
}

/* Buttons */
.management-controls {
    margin: 20px 0;
    display: flex;
    gap: 12px;
}

button {
    padding: 10px 16px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    font-size: 14px;
    transition: background 0.2s;
}

.btn-primary { background-color: var(--text-main); color: var(--bg-main); }
.btn-primary:hover { background-color: var(--accent-color); }

.btn-secondary { background-color: var(--border-color); color: var(--text-main); }
.btn-secondary:hover { background-color: var(--accent-color); color: var(--bg-main); }

.btn-text-only {
    background: none;
    color: var(--accent-color);
    padding: 0;
    font-size: 15px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.btn-text-only:hover { background: none; color: var(--text-main); }

/* Modal Styling */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: rgba(43, 43, 43, 0.4);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.modal-content {
    background: var(--bg-main);
    padding: 30px;
    border-radius: 16px;
    width: 100%;
    max-width: 450px;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    border: 1px solid var(--border-color);
}

.modal-content h2 {
    margin-top: 0;
    border-bottom: none;
    padding-bottom: 0;
}

.form-group {
    margin-bottom: 20px;
    display: flex;
    flex-direction: column;
}

.form-group label {
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-main);
    font-size: 14px;
}

.form-group input[type="text"],
.form-group input[type="email"],
.form-group input[type="password"] {
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 15px;
    background-color: var(--bg-main);
    color: var(--text-main);
    font-family: inherit;
    box-sizing: border-box;
}

.form-group textarea {
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 15px;
    background-color: var(--bg-main);
    color: var(--text-main);
    font-family: inherit;
    resize: vertical;
    box-sizing: border-box;
}

/* Styled File Input */
.form-group input[type="file"] {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 10px;
    background-color: var(--bg-main);
    color: var(--accent-color);
    font-size: 14px;
    width: 100%;
    box-sizing: border-box;
}

.form-group input[type="file"]::file-selector-button {
    padding: 8px 14px;
    margin-right: 12px;
    border: none;
    border-radius: 8px;
    background-color: var(--border-color);
    color: var(--text-main);
    font-weight: 600;
    font-size: 13px;
    cursor: pointer;
    transition: background 0.2s;
}

.form-group input[type="file"]::file-selector-button:hover {
    background-color: var(--accent-color);
    color: var(--bg-main);
}

/* Safari fallback */
.form-group input[type="file"]::-webkit-file-upload-button {
    padding: 8px 14px;
    margin-right: 12px;
    border: none;
    border-radius: 8px;
    background-color: var(--border-color);
    color: var(--text-main);
    font-weight: 600;
    font-size: 13px;
    cursor: pointer;
    transition: background 0.2s;
}

.modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: 12px;
    margin-top: 30px;
}

.form-error {
    color: #b93a3a;
    font-size: 13px;
    font-weight: 600;
    margin: 4px 0 0 0;
}

/* --- Auth screen --- */
.auth-wrapper {
    min-height: 100vh;
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--bg-main);
    box-sizing: border-box;
}

.auth-card {
    background: var(--bg-sidebar);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 40px;
    width: 100%;
    max-width: 380px;
    text-align: center;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.06);
    box-sizing: border-box;
}

.auth-logo {
    max-width: 90px;
    height: auto;
    margin-bottom: 12px;
}

.auth-card h1 {
    font-size: 20px;
    margin-bottom: 24px;
}

.auth-card .form-group {
    text-align: left;
}

.auth-submit-btn {
    width: 100%;
    margin-top: 4px;
    box-sizing: border-box;
}

.auth-info {
    color: var(--text-main);
    font-size: 13px;
    margin: 6px 0 0 0;
}

.auth-toggle {
    margin-top: 20px;
    font-size: 13px;
    color: var(--accent-color);
}

.auth-toggle a {
    color: var(--text-main);
    font-weight: 600;
    text-decoration: none;
    margin-left: 4px;
}

.auth-toggle a:hover {
    text-decoration: underline;
}

/* --- Duration presets (New Room modal) --- */
.preset-btn-row {
    display: flex;
    gap: 8px;
    margin-bottom: 10px;
}

.btn-preset {
    background-color: var(--bg-main);
    color: var(--text-main);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 6px 14px;
    font-size: 13px;
    font-weight: 600;
}

.btn-preset:hover { background-color: var(--accent-color); color: var(--bg-main); }

.btn-preset.active {
    background-color: var(--text-main);
    color: var(--bg-main);
    border-color: var(--text-main);
}

.datetime-row {
    display: flex;
    gap: 12px;
}

.datetime-field {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.datetime-field label {
    font-size: 12px;
    font-weight: 600;
    color: var(--accent-color);
    margin-bottom: 4px;
}

.datetime-field input[type="datetime-local"] {
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 14px;
    background-color: var(--bg-main);
    color: var(--text-main);
    box-sizing: border-box;
    width: 100%;
}

.access-mode-hint { font-size: 12px; color: var(--accent-color); margin: 6px 0 0 0; }

.modal-subtext { color: var(--accent-color); font-size: 13px; margin: -8px 0 20px 0; }
.roster-count-text { font-size: 13px; color: var(--text-main); margin: 12px 0 0 0; font-weight: 600; }

.access-mode-chip {
    font-size: 11px;
    color: var(--accent-color);
    display: flex;
    align-items: center;
    gap: 4px;
}

/* --- Previous Discussion Rooms list --- */
.room-card {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 16px;
    background: var(--bg-sidebar);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 16px 20px;
    margin-bottom: 12px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.room-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 12px -3px rgba(0, 0, 0, 0.08);
    border-color: var(--accent-color);
}

.room-card h3 { margin: 0 0 6px 0; }
.room-prompt { margin: 0 0 6px 0; color: var(--text-main); }
.room-dates { margin: 0; font-size: 12px; color: var(--accent-color); }

.room-card-side {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 8px;
    flex-shrink: 0;
}

.room-status {
    font-size: 12px;
    font-weight: 700;
    padding: 4px 10px;
    border-radius: 12px;
    text-transform: uppercase;
    letter-spacing: 0.02em;
}

.status-open { background-color: #dff0d8; color: #3c763d; }
.status-scheduled { background-color: #fcf8e3; color: #8a6d3b; }
.status-closed { background-color: var(--border-color); color: var(--text-main); }

.room-code-badge {
    font-family: monospace;
    font-weight: 700;
    letter-spacing: 0.05em;
    background-color: var(--bg-main);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 4px 10px;
}

/* ===================== STUDENT / INDEX PAGE ===================== */
.saber-student-page {
    max-width: 720px;
    margin: 0 auto;
    padding: 40px 20px;
    min-height: 100vh;
    box-sizing: border-box;
}

.hidden { display: none !important; }

.student-topbar {
    display: flex;
    justify-content: flex-end;
    margin-bottom: 20px;
}

.student-topbar a {
    color: var(--accent-color);
    text-decoration: none;
    font-size: 13px;
    font-weight: 600;
    transition: color 0.2s;
}
.student-topbar a:hover { color: var(--text-main); }

.student-header { text-align: center; margin-bottom: 32px; }
.student-header h1 { font-size: 2.2rem; letter-spacing: -0.02em; margin: 0 0 4px 0; }

.student-eyebrow {
    color: var(--accent-color);
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    font-size: 11px;
    margin: 0 0 12px 0;
}

.student-subtitle { color: var(--accent-color); margin: 0; font-size: 14px; }

.saber-panel {
    background: var(--bg-sidebar);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 32px;
    box-shadow: 0 10px 25px -8px rgba(0, 0, 0, 0.06);
    box-sizing: border-box;
}

.saber-input {
    width: 100%;
    box-sizing: border-box;
    padding: 14px;
    border: 1px solid var(--border-color);
    border-radius: 10px;
    font-size: 16px;
    background-color: var(--bg-main);
    color: var(--text-main);
    margin-bottom: 16px;
    font-family: inherit;
}

.saber-input.code-input {
    text-transform: uppercase;
    text-align: center;
    font-weight: 700;
    letter-spacing: 0.1em;
    font-size: 18px;
}

.saber-input.name-input { text-align: center; }

.btn-cta {
    width: 100%;
    box-sizing: border-box;
    padding: 16px;
    font-size: 16px;
    border-radius: 10px;
}

.status-message { text-align: center; font-size: 14px; font-weight: 600; margin-top: 16px; }
.status-message.error { color: #b93a3a; }
.status-message.info { color: var(--text-main); }

.prompt-callout {
    background: var(--bg-main);
    border-left: 4px solid var(--text-main);
    border-radius: 8px;
    padding: 16px 20px;
    margin-bottom: 24px;
}

.prompt-callout h3 {
    margin: 0 0 6px 0;
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--accent-color);
}

.prompt-callout p { margin: 0; font-size: 17px; color: var(--text-main); }

.paste-warning-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
    font-size: 12px;
}

.paste-warning-row .warning { color: #b93a3a; font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em; }
.paste-warning-row .hint { color: var(--accent-color); }

.feed-shell { display: flex; flex-direction: column; height: 78vh; }

.feed-topbar {
    background: var(--bg-sidebar);
    border: 1px solid var(--border-color);
    border-bottom: none;
    border-radius: 16px 16px 0 0;
    padding: 16px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.feed-topbar h2 { margin: 0; font-size: 16px; }

.teacher-view-badge {
    background-color: var(--text-main);
    color: var(--bg-main);
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 4px 10px;
    border-radius: 12px;
    margin-left: 10px;
}

.feed-body {
    flex: 1;
    overflow-y: auto;
    background: var(--bg-main);
    border: 1px solid var(--border-color);
    border-radius: 0 0 16px 16px;
    padding: 24px;
}

.post-card {
    background: var(--bg-sidebar);
    border: 1px solid var(--border-color);
    border-radius: 14px;
    padding: 20px;
    margin-bottom: 20px;
}

.post-card-reply-wrap {
    margin-left: 20px;
    margin-top: 14px;
    padding-left: 16px;
    border-left: 2px solid var(--border-color);
}

.post-card-reply {
    background: var(--bg-main);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 14px 16px;
}

.post-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 8px; }
.post-author { font-weight: 700; color: var(--text-main); }
.post-author.small { font-size: 14px; }
.reply-badge { font-size: 11px; color: var(--accent-color); font-weight: 700; margin-left: 8px; text-transform: uppercase; }
.post-time { font-size: 12px; color: var(--accent-color); }
.post-content { margin: 0 0 10px 0; color: var(--text-main); white-space: pre-wrap; line-height: 1.5; }
.post-content.small { font-size: 14px; }

.reply-toggle-btn {
    background: none;
    border: none;
    padding: 0;
    color: var(--text-main);
    font-weight: 700;
    font-size: 13px;
    cursor: pointer;
}
.reply-toggle-btn:hover { color: var(--accent-color); background: none; }

.reply-ui { margin-top: 12px; padding-left: 14px; border-left: 2px solid var(--accent-color); }

.reply-ui textarea {
    width: 100%;
    box-sizing: border-box;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 14px;
    font-family: inherit;
    margin-bottom: 8px;
    background: var(--bg-sidebar);
    color: var(--text-main);
}

.reply-ui-actions { display: flex; gap: 8px; }
.reply-ui-actions button { font-size: 13px; padding: 8px 14px; }

.instructor-badge {
    background: var(--text-main);
    color: var(--bg-main);
    font-size: 10px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 2px 8px;
    border-radius: 10px;
    margin-left: 8px;
}

.email-login-link { text-align: center; font-size: 13px; margin-top: 14px; }
.email-login-link a { color: var(--accent-color); text-decoration: none; font-weight: 600; }
.email-login-link a:hover { color: var(--text-main); }