/* styles.css */
:root {
    --bg-color: #f0f2f5;
    --card-bg: #ffffff;
    --text-color: #1a1a2e;
    --border-color: #e2e8f0;
    --item-bg: #f8fafc;
    --meta-text: #64748b;
    --accent: #6366f1;
    --accent-light: #818cf8;
    --danger: #ef4444;
    --success: #10b981;
}

[data-theme="dark"] {
    --bg-color: #0f1117;
    --card-bg: #1a1d2e;
    --text-color: #e2e8f0;
    --border-color: #2d3348;
    --item-bg: #232740;
    --meta-text: #8b92a8;
    --accent: #818cf8;
    --accent-light: #a5b4fc;
    --danger: #f87171;
    --success: #34d399;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--bg-color);
    min-height: 100vh;
    padding: 20px;
    transition: background 0.3s;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background: var(--card-bg);
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
    overflow: hidden;
}

.header {
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    color: var(--text-color);
    padding: 30px;
    text-align: center;
    position: relative;
}

.header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    background: var(--item-bg);
    border: 1.5px solid var(--border-color);
    border-radius: 50%;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 20px;
    padding: 0;
    transition: all 0.2s;
}

.theme-toggle:hover {
    border-color: var(--accent);
    transform: rotate(15deg) scale(1.1);
    box-shadow: none;
}

.login-container, .app-container {
    display: none;
    padding: 30px;
}

.login-container.active, .app-container.active {
    display: block;
}

.form-group {
    margin-bottom: 20px;
}

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

input, select {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    font-size: 16px;
    transition: border-color 0.3s, background 0.3s;
    background: var(--card-bg);
    color: var(--text-color);
}

input:focus, select:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

button {
    background: var(--accent);
    color: white;
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    width: auto;
    transition: all 0.2s;
}

button:hover {
    background: var(--accent-light);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
}

.error-message {
    color: #e74c3c;
    margin-top: 10px;
    text-align: center;
    display: none;
}

.success-message {
    color: #27ae60;
    margin-top: 10px;
    text-align: center;
    display: none;
}

/* Larger todo input area */
.todo-input-group {
    display: flex;
    gap: 10px;
    margin-bottom: 25px;
    align-items: stretch;
}

.todo-input-group input {
    flex: 1;
    min-width: 200px;
    max-width: 100%;
    padding: 12px 16px;
    font-size: 16px;
    border-width: 2px;
}

.todo-input-group button[type="submit"] {
    padding: 12px 28px;
    font-size: 15px;
    white-space: nowrap;
}

.todos-list {
    list-style: none;
    max-height: 600px;
    overflow-y: auto;
}

.todo-item {
    background: var(--item-bg);
    border-radius: 12px;
    padding: 25px;
    margin-bottom: 18px;
    display: flex;
    align-items: center;
    gap: 15px;
    transition: transform 0.2s, box-shadow 0.2s;
}

.todo-item:hover {
    transform: translateX(5px);
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

.todo-checkbox {
    width: 22px;
    height: 22px;
    cursor: pointer;
    accent-color: var(--accent);
    flex-shrink: 0;
}

.todo-content {
    flex: 1;
}

.todo-text {
    font-size: 19px;
    color: var(--text-color);
    margin-bottom: 8px;
    line-height: 1.4;
}

.todo-text.completed {
    text-decoration: line-through;
    color: #999;
}

.todo-meta {
    display: flex;
    gap: 20px;
    font-size: 14px;
    color: var(--meta-text);
}

.todo-actions {
    display: flex;
    gap: 10px;
}

.btn-small {
    padding: 10px 16px;
    font-size: 14px;
    width: auto;
}

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

.btn-assign {
    background: transparent;
    border: 1.5px solid var(--border-color);
    color: var(--meta-text);
    padding: 8px 12px;
    font-size: 13px;
    cursor: pointer;
}

.btn-assign:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: rgba(99, 102, 241, 0.05);
    box-shadow: none;
    transform: none;
}

.btn-assign.has-assignee {
    border-color: var(--accent);
    color: var(--accent);
    background: rgba(99, 102, 241, 0.08);
}

.user-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 25px;
    padding: 18px;
    background: var(--item-bg);
    border-radius: 12px;
}

.logout-btn {
    background: var(--danger);
    width: auto;
}

/* Assignee icon button */
.assignee-icon {
    padding: 12px 16px;
    font-size: 18px;
    width: auto;
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.2s;
}

.assignee-icon:hover {
    border-color: #667eea;
    transform: translateY(-2px);
}

/* Assignee popup modal */
.assignee-popup-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: none;
    justify-content: center;
    align-items: flex-start;
    padding-top: 100px;
    z-index: 1000;
}

.assignee-popup-overlay.active {
    display: flex;
}

.popup-content {
    background: var(--card-bg);
    border-radius: 15px;
    padding: 20px;
    min-width: 300px;
    max-width: 400px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
}

.popup-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 2px solid var(--border-color);
}

.popup-header h3 {
    color: var(--text-color);
    font-size: 18px;
}

.close-popup-btn {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--meta-text);
    padding: 0;
    width: auto;
}

.close-popup-btn:hover {
    color: #e74c3c;
}

#assigneeList {
    list-style: none;
    max-height: 300px;
    overflow-y: auto;
}

.assignee-option {
    padding: 12px 15px;
    cursor: pointer;
    border-radius: 8px;
    transition: background 0.2s;
    display: flex;
    align-items: center;
    gap: 10px;
}

.assignee-option:hover {
    background: var(--item-bg);
}

.assignee-option.selected {
    background: #667eea20;
    border-left: 3px solid #667eea;
}

.clear-assignment-btn {
    margin-top: 15px;
    width: 100%;
    padding: 10px;
    background: transparent;
    color: var(--meta-text);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
}

.clear-assignment-btn:hover {
    background: #e74c3c10;
    color: #e74c3c;
    border-color: #e74c3c;
}

@media (max-width: 600px) {
    body {
        padding: 15px;
    }

    .header h1 {
        font-size: 2em;
    }

    .todo-input-group {
        flex-direction: column;
    }

    .todo-item {
        flex-direction: column;
        align-items: flex-start;
    }

    .todo-actions {
        width: 100%;
        justify-content: space-between;
    }
}