/* Modern, Glassmorphism CSS */
:root {
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --bg-gradient-start: #0f172a;
    --bg-gradient-end: #1e1b4b;
    --glass-bg: rgba(255, 255, 255, 0.05);
    --glass-border: rgba(255, 255, 255, 0.1);
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --danger: #ef4444;
    --success: #10b981;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
}

body {
    background: linear-gradient(135deg, var(--bg-gradient-start), var(--bg-gradient-end));
    color: var(--text-main);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* Glassmorphism Card */
.glass-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
    padding: 2rem;
}

/* Login/Register Forms */
.auth-container {
    width: 100%;
    max-width: 400px;
}

.auth-container h2 {
    text-align: center;
    margin-bottom: 1.5rem;
    font-weight: 600;
}

.input-group {
    margin-bottom: 1rem;
}

.input-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-muted);
    font-size: 0.875rem;
}

.input-group input, .input-group textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    color: var(--text-main);
    outline: none;
    transition: border-color 0.3s;
}

.input-group input:focus, .input-group textarea:focus {
    border-color: var(--primary);
}

.btn {
    width: 100%;
    padding: 0.75rem;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.3s, transform 0.1s;
}

.btn:hover {
    background: var(--primary-hover);
}

.btn:active {
    transform: scale(0.98);
}

.toggle-form {
    text-align: center;
    margin-top: 1rem;
    font-size: 0.875rem;
    color: var(--text-muted);
}

.toggle-form a {
    color: var(--primary);
    text-decoration: none;
    cursor: pointer;
}

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

/* Dashboard Layout */
.dashboard-layout {
    display: flex;
    width: 100vw;
    height: 100vh;
    padding: 1rem;
    gap: 1rem;
}

.sidebar {
    width: 250px;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.main-content {
    flex: 1;
    display: flex;
    gap: 1rem;
    overflow: hidden;
}

.email-list-pane {
    width: 350px;
    display: flex;
    flex-direction: column;
    overflow-y: auto;
}

.email-view-pane {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow-y: auto;
}

/* Nav Items */
.nav-item {
    padding: 0.75rem 1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: background 0.2s;
    color: var(--text-main);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-item:hover, .nav-item.active {
    background: rgba(255, 255, 255, 0.1);
}

/* Email Items */
.email-item {
    padding: 1rem;
    border-bottom: 1px solid var(--glass-border);
    cursor: pointer;
    transition: background 0.2s;
}

.email-item:hover {
    background: rgba(255, 255, 255, 0.05);
}

.email-item.unread {
    font-weight: bold;
    color: white;
}

.email-item .sender {
    font-size: 0.875rem;
    margin-bottom: 0.25rem;
}

.email-item .subject {
    font-size: 1rem;
    color: var(--text-main);
}

/* Compose Modal (hidden by default) */
.modal {
    display: none;
    position: fixed;
    top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(0,0,0,0.5);
    backdrop-filter: blur(4px);
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.modal.active {
    display: flex;
}

.compose-box {
    width: 100%;
    max-width: 600px;
}

.toast {
    position: fixed;
    bottom: 20px;
    right: 20px;
    padding: 1rem 1.5rem;
    border-radius: 8px;
    background: var(--success);
    color: white;
    transform: translateY(100px);
    opacity: 0;
    transition: all 0.3s ease;
    z-index: 2000;
}

.toast.show {
    transform: translateY(0);
    opacity: 1;
}

.toast.error {
    background: var(--danger);
}