:root {
    /* Light Theme - Duolingo inspired */
    --bg-color: #ffffff;
    --text-color: #4b4b4b;
    --text-light: #777777;
    --card-bg: #ffffff;
    --border-color: #e5e5e5;
    
    --primary-color: #8e24aa;
    --primary-shadow: #6a1b9a;
    --primary-hover: #ab47bc;
    
    --secondary-color: #1cb0f6;
    --secondary-shadow: #1899d6;
    
    --danger-color: #ff4b4b;
    --danger-shadow: #ea2b2b;
    
    --streak-color: #ff9600;
    --streak-bg: rgba(255, 150, 0, 0.1);
    
    --nav-bg: #ffffff;
    --nav-border: #e5e5e5;
    --nav-inactive: #afafaf;
}

[data-theme="dark"] {
    /* Dark Theme */
    --bg-color: #131f24;
    --text-color: #ffffff;
    --text-light: #afafaf;
    --card-bg: #202f36;
    --border-color: #37464f;
    
    --nav-bg: #131f24;
    --nav-border: #37464f;
    --nav-inactive: #777777;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Nunito', sans-serif;
    -webkit-tap-highlight-color: transparent;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s, color 0.3s;
    overflow-x: hidden;
}

#app {
    display: flex;
    flex-direction: column;
    height: 100vh;
    max-width: 600px;
    margin: 0 auto;
    position: relative;
    background-color: var(--bg-color);
}

/* Header */
.top-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 20px;
    border-bottom: 2px solid var(--border-color);
    background-color: var(--bg-color);
    z-index: 10;
}

.streak-container {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 800;
    font-size: 1.2rem;
    color: var(--streak-color);
    background: var(--streak-bg);
    padding: 6px 12px;
    border-radius: 12px;
}

.user-greeting {
    font-weight: 700;
    color: var(--text-color);
}

/* Main Content */
#main-content {
    flex: 1;
    overflow-y: auto;
    padding: 24px 20px;
    padding-bottom: 100px; /* Space for bottom nav */
}

.view {
    display: none;
    animation: fadeIn 0.3s ease-out;
}

.view.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.view-title {
    font-size: 1.8rem;
    font-weight: 800;
    margin-bottom: 20px;
    color: var(--text-color);
}

/* Daily Text Card */
.daily-text-card {
    background-color: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 20px;
    padding: 24px;
    margin-bottom: 30px;
    text-align: center;
    box-shadow: 0 4px 0 var(--border-color);
}

#daily-text-date {
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 16px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.daily-text-quote {
    font-size: 1.4rem;
    font-weight: 700;
    line-height: 1.5;
    margin-bottom: 20px;
}

.daily-text-source {
    font-size: 1.1rem;
    font-weight: 800;
    color: var(--secondary-color);
}

.action-container {
    display: flex;
    flex-direction: column;
    align-items: center;
}

/* Buttons */
.btn {
    border: none;
    outline: none;
    cursor: pointer;
    font-family: inherit;
    font-weight: 800;
    border-radius: 16px;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: all 0.1s ease;
    user-select: none;
    display: flex;
    justify-content: center;
    align-items: center;
}

.btn-chunky {
    width: 100%;
    padding: 16px;
    font-size: 1.2rem;
}

.btn-small {
    padding: 10px 16px;
    font-size: 1rem;
    border-radius: 12px;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    border-bottom: 5px solid var(--primary-shadow);
}

.btn-primary:active, .btn-primary.pressed {
    transform: translateY(5px);
    border-bottom: 0px solid var(--primary-shadow);
    margin-bottom: 5px;
}

.btn-secondary {
    background-color: var(--secondary-color);
    color: white;
    border-bottom: 4px solid var(--secondary-shadow);
}
.btn-secondary:active, .btn-secondary.pressed {
    transform: translateY(4px);
    border-bottom: 0px solid var(--secondary-shadow);
    margin-bottom: 4px;
}

.btn-danger {
    background-color: var(--danger-color);
    color: white;
    border-bottom: 4px solid var(--danger-shadow);
}
.btn-danger:active {
    transform: translateY(4px);
    border-bottom: 0px solid var(--danger-shadow);
    margin-bottom: 4px;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: translateY(5px);
    border-bottom: 0px;
    margin-bottom: 5px;
}

.status-msg {
    margin-top: 16px;
    font-weight: 700;
    color: var(--text-light);
}

/* Friends List */
.friend-card {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 16px;
    padding: 16px;
    margin-bottom: 12px;
}

.friend-info {
    display: flex;
    align-items: center;
    gap: 12px;
}

.friend-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background-color: #e5e5e5;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    color: #4b4b4b;
}

.friend-details {
    display: flex;
    flex-direction: column;
}

.friend-name {
    font-weight: 800;
    font-size: 1.1rem;
}

.friend-streak {
    color: var(--streak-color);
    font-weight: 700;
    font-size: 0.9rem;
}

/* Settings */
.settings-card {
    background-color: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 20px;
    padding: 20px;
}

.setting-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 0;
    border-bottom: 2px solid var(--border-color);
    gap: 12px;
}

.setting-item:last-child {
    border-bottom: none;
}

.setting-item label {
    font-weight: 700;
    font-size: 1.1rem;
}

.input-field {
    flex: 1;
    padding: 10px;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    background: var(--bg-color);
    color: var(--text-color);
    font-family: inherit;
    font-weight: 600;
    font-size: 1rem;
    outline: none;
}

.input-field:focus {
    border-color: var(--secondary-color);
}

/* Toggle Switch */
.toggle-switch {
    position: relative;
    display: inline-block;
    width: 50px;
    height: 28px;
}

.toggle-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--border-color);
    transition: .4s;
    border-radius: 34px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 20px;
    width: 20px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    transition: .4s;
    border-radius: 50%;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

input:checked + .slider {
    background-color: var(--primary-color);
}

input:checked + .slider:before {
    transform: translateX(22px);
}

/* Bottom Nav */
.bottom-nav {
    display: flex;
    justify-content: space-around;
    align-items: center;
    position: fixed;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100%;
    max-width: 600px;
    background-color: var(--nav-bg);
    border-top: 2px solid var(--nav-border);
    padding: 12px 0;
    z-index: 10;
}

.nav-item {
    background: none;
    border: none;
    outline: none;
    color: var(--nav-inactive);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    cursor: pointer;
    font-family: inherit;
    font-weight: 700;
    font-size: 0.8rem;
    transition: color 0.2s;
    flex: 1;
}

.nav-item.active {
    color: var(--primary-color);
}

.nav-icon-wrapper {
    font-size: 1.5rem;
    position: relative;
    transition: transform 0.2s;
}

.nav-item.active .nav-icon-wrapper {
    animation: bounce 0.5s;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-3px); }
}

.hidden {
    display: none !important;
}

/* Modal */
.modal {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background-color: rgba(0,0,0,0.6);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 100;
    padding: 20px;
}

.modal-content {
    background-color: var(--bg-color);
    border: 2px solid var(--border-color);
    border-radius: 24px;
    padding: 30px;
    text-align: center;
    width: 100%;
    max-width: 400px;
    z-index: 101;
    animation: popIn 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

@keyframes popIn {
    0% { transform: scale(0.8); opacity: 0; }
    100% { transform: scale(1); opacity: 1; }
}

.modal-icon {
    font-size: 4rem;
    color: #ffc800;
    margin-bottom: 16px;
    text-shadow: 0 4px 0 #d9a900;
}

.modal-content h2 {
    font-size: 2rem;
    font-weight: 900;
    color: var(--primary-color);
    margin-bottom: 12px;
}

.modal-content p {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 24px;
}

/* Friends Grid */
.friends-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

.friend-grid-card {
    background-color: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 20px 10px;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.friend-grid-avatar {
    width: 65px;
    height: 65px;
    border-radius: 50%;
    background-color: #e5e5e5;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 2.2rem;
    color: #555;
    margin-bottom: 15px;
    cursor: pointer;
    transition: transform 0.2s;
}

.friend-grid-avatar:hover {
    transform: scale(1.05);
}

.friend-grid-name {
    font-weight: 900;
    font-size: 1.15rem;
    margin-bottom: 5px;
    color: var(--text-color);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 100%;
}

.friend-grid-streak {
    color: var(--streak-color);
    font-weight: 800;
    font-size: 0.95rem;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 5px;
}

.friend-grid-actions {
    display: flex;
    gap: 8px;
    width: 100%;
    justify-content: center;
}

.friend-grid-actions .btn {
    flex: 1;
    font-size: 0.75rem;
    padding: 8px 0;
    text-transform: uppercase;
    font-weight: 800;
}
.confetti-container {
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    pointer-events: none;
    z-index: 100;
    overflow: hidden;
}

.confetti {
    position: absolute;
    width: 10px;
    height: 10px;
    background-color: #f00;
    animation: fall linear forwards;
}

@keyframes fall {
    to { transform: translateY(100vh) rotate(720deg); }
}

/* Toasts */
#toast-container {
    position: fixed;
    top: 80px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    gap: 10px;
    z-index: 50;
    pointer-events: none;
    width: 90%;
    max-width: 400px;
}

.toast {
    background-color: var(--secondary-color);
    color: white;
    padding: 12px 20px;
    border-radius: 12px;
    font-weight: 800;
    text-align: center;
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
    animation: slideDown 0.3s ease-out, fadeOut 0.3s 2.7s ease-in forwards;
}

@keyframes slideDown {
    from { transform: translateY(-20px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}
@keyframes fadeOut {
    to { opacity: 0; }
}

/* Chat Messages */
.chat-bubble {
    padding: 10px 14px;
    border-radius: 16px;
    max-width: 80%;
    word-break: break-word;
    font-weight: 600;
}
.chat-bubble.sent {
    background-color: var(--primary-color);
    color: white;
    align-self: flex-end;
    border-bottom-right-radius: 4px;
}
.chat-bubble.received {
    background-color: var(--card-bg);
    border: 2px solid var(--border-color);
    color: var(--text-color);
    align-self: flex-start;
    border-bottom-left-radius: 4px;
}
.chat-timestamp {
    font-size: 0.7rem;
    opacity: 0.7;
    margin-top: 4px;
    text-align: right;
}
.message-preview {
    font-size: 0.85rem;
    color: var(--text-light);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 150px;
}

/* === Quiz Styles === */
.quiz-answer-btn {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px 20px;
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 14px;
    font-family: 'Nunito', sans-serif;
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-color);
    text-align: left;
    cursor: pointer;
    transition: border-color 0.15s, background 0.15s, transform 0.12s;
    width: 100%;
    box-shadow: 0 3px 0 var(--border-color);
}

.quiz-answer-btn:hover:not(:disabled) {
    border-color: var(--secondary-color);
    transform: translateY(-1px);
}

.quiz-answer-btn:active:not(:disabled) {
    transform: translateY(2px);
    box-shadow: none;
}

.quiz-answer-btn .quiz-letter {
    min-width: 36px;
    height: 36px;
    border-radius: 8px;
    background: var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 900;
    font-size: 1rem;
    color: var(--text-light);
    transition: background 0.15s, color 0.15s;
}

.quiz-answer-btn.correct {
    border-color: #58cc02;
    background: rgba(88, 204, 2, 0.12);
}
.quiz-answer-btn.correct .quiz-letter {
    background: #58cc02;
    color: white;
}

.quiz-answer-btn.wrong {
    border-color: #ff4b4b;
    background: rgba(255, 75, 75, 0.12);
}
.quiz-answer-btn.wrong .quiz-letter {
    background: #ff4b4b;
    color: white;
}

.quiz-result-correct {
    background: rgba(88, 204, 2, 0.15);
    border: 2px solid #58cc02;
    color: #58cc02;
}
.quiz-result-wrong {
    background: rgba(255, 75, 75, 0.15);
    border: 2px solid #ff4b4b;
    color: #ff4b4b;
}

@keyframes quiz-bounce {
    0% { transform: scale(1); }
    30% { transform: scale(1.06); }
    60% { transform: scale(0.97); }
    100% { transform: scale(1); }
}

.quiz-answer-btn.correct, .quiz-answer-btn.wrong {
    animation: quiz-bounce 0.3s ease;
}