:root {
    --bg-color: #0f172a;
    --text-color: #e2e8f0;
    --accent-color: #3b82f6;
    --accent-hover: #2563eb;
    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
    --danger-color: #ef4444;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background-image: radial-gradient(circle at top right, rgba(59, 130, 246, 0.15), transparent 40%),
                      radial-gradient(circle at bottom left, rgba(139, 92, 246, 0.15), transparent 40%);
}

.container {
    width: 100%;
    max-width: 800px;
    padding: 2rem;
}

.glass-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    animation: fadeIn 0.5s ease-out;
}

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

header {
    text-align: center;
    margin-bottom: 2rem;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(to right, #60a5fa, #a78bfa);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
}

/* Forms */
.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    color: #94a3b8;
}

input[type="text"],
input[type="password"],
textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid var(--glass-border);
    border-radius: 0.5rem;
    color: var(--text-color);
    outline: none;
    transition: border-color 0.3s, box-shadow 0.3s;
}

input:focus,
textarea:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

button {
    width: 100%;
    padding: 0.75rem 1rem;
    background: var(--accent-color);
    color: #fff;
    border: none;
    border-radius: 0.5rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.1s;
}

button:hover {
    background: var(--accent-hover);
}

button:active {
    transform: scale(0.98);
}

/* Auth Toggle */
.auth-toggle {
    text-align: center;
    margin-top: 1rem;
    font-size: 0.875rem;
    color: #94a3b8;
}

.auth-toggle a {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
}

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

/* Dashboard */
.dashboard-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.dashboard-header h2 {
    font-size: 1.5rem;
    font-weight: 600;
}

.btn-logout {
    width: auto;
    padding: 0.5rem 1rem;
    background: transparent;
    border: 1px solid var(--glass-border);
    color: #94a3b8;
}

.btn-logout:hover {
    background: rgba(255, 255, 255, 0.05);
}

/* Notes List */
.notes-container {
    margin-top: 2rem;
    display: grid;
    gap: 1rem;
}

.note-card {
    background: rgba(15, 23, 42, 0.4);
    border: 1px solid var(--glass-border);
    border-radius: 0.75rem;
    padding: 1.5rem;
    position: relative;
    transition: transform 0.2s, box-shadow 0.2s;
    animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
    from { opacity: 0; transform: translateX(-20px); }
    to { opacity: 1; transform: translateX(0); }
}

.note-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
}

.note-content {
    white-space: pre-wrap;
    line-height: 1.6;
    margin-bottom: 1rem;
}

.note-meta {
    font-size: 0.75rem;
    color: #64748b;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.btn-delete {
    width: auto;
    padding: 0.25rem 0.5rem;
    background: transparent;
    color: var(--danger-color);
    border: 1px solid transparent;
}

.btn-delete:hover {
    background: rgba(239, 68, 68, 0.1);
    border-color: rgba(239, 68, 68, 0.2);
}

/* Error/Success Messages */
.message {
    padding: 0.75rem;
    border-radius: 0.5rem;
    margin-bottom: 1rem;
    font-size: 0.875rem;
    display: none;
}

.message.error {
    display: block;
    background: rgba(239, 68, 68, 0.1);
    color: #fca5a5;
    border: 1px solid rgba(239, 68, 68, 0.2);
}

/* Loader */
.loader {
    border: 3px solid rgba(255,255,255,0.1);
    border-top: 3px solid var(--accent-color);
    border-radius: 50%;
    width: 24px;
    height: 24px;
    animation: spin 1s linear infinite;
    margin: 0 auto;
    display: none;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}