/* ========== BUTTONS ========== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 12px 24px;
    border: none;
    border-radius: var(--radius-lg);
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    font-family: inherit;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: white;
    box-shadow: 0 4px 20px rgba(6, 182, 212, 0.4);
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 30px rgba(6, 182, 212, 0.6);
}

.btn-primary:active:not(:disabled) {
    transform: translateY(0);
}

.btn-secondary {
    background: rgba(6, 182, 212, 0.1);
    color: var(--primary);
    border: 1px solid var(--border-primary);
}

.btn-secondary:hover:not(:disabled) {
    background: rgba(6, 182, 212, 0.2);
    border-color: var(--primary);
    transform: translateY(-2px);
}

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
}

.btn-ghost:hover:not(:disabled) {
    background: rgba(148, 163, 184, 0.1);
    color: var(--text-primary);
}

.btn-danger {
    background: rgba(239, 68, 68, 0.2);
    color: var(--error);
    border: 1px solid rgba(239, 68, 68, 0.3);
}

.btn-danger:hover:not(:disabled) {
    background: rgba(239, 68, 68, 0.3);
    border-color: var(--error);
}

.btn-success {
    background: rgba(16, 185, 129, 0.2);
    color: var(--success);
    border: 1px solid rgba(16, 185, 129, 0.3);
}

.btn-success:hover:not(:disabled) {
    background: rgba(16, 185, 129, 0.3);
    border-color: var(--success);
}

/* ========== FORM INPUTS ========== */
.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.form-label i {
    color: var(--primary);
    font-size: 14px;
}

.input-wrapper {
    position: relative;
}

.form-input {
    width: 100%;
    padding: 14px 16px;
    padding-left: 44px;
    background: rgba(15, 23, 42, 0.6);
    border: 2px solid var(--border-primary);
    border-radius: var(--radius-md);
    color: var(--text-bright);
    font-size: 15px;
    font-family: inherit;
    transition: var(--transition);
    outline: none;
}

.form-input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(6, 182, 212, 0.1);
}

.form-input::placeholder {
    color: var(--text-tertiary);
}

.form-input.error {
    border-color: var(--error);
}

.form-input.success {
    border-color: var(--success);
}

.input-icon {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-tertiary);
    pointer-events: none;
    transition: var(--transition);
}

.form-input:focus + .input-icon,
.form-input:not(:placeholder-shown) + .input-icon {
    color: var(--primary);
}

.input-status {
    position: absolute;
    right: 16px;
    top: 50%;
    transform: translateY(-50%);
    display: none;
}

.input-status.show {
    display: block;
}

.input-status.checking {
    color: var(--warning);
}

.input-status.available {
    color: var(--success);
}

.input-status.unavailable {
    color: var(--error);
}

.password-toggle {
    position: absolute;
    right: 16px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--text-tertiary);
    cursor: pointer;
    padding: 4px;
    transition: var(--transition);
}

.password-toggle:hover {
    color: var(--primary);
}

.form-hint {
    display: block;
    font-size: 12px;
    color: var(--text-tertiary);
    margin-top: 6px;
}

.form-error {
    display: block;
    font-size: 12px;
    color: var(--error);
    margin-top: 6px;
    min-height: 16px;
}

/* ========== PASSWORD STRENGTH ========== */
.password-strength {
    display: flex;
    gap: 4px;
    margin-top: 8px;
    height: 4px;
}

.strength-bar {
    flex: 1;
    background: rgba(148, 163, 184, 0.2);
    border-radius: 2px;
    transition: var(--transition);
}

.strength-bar.active.weak {
    background: var(--error);
}

.strength-bar.active.medium {
    background: var(--warning);
}

.strength-bar.active.strong {
    background: var(--success);
}

/* ========== CHECKBOX ========== */
.checkbox-group {
    margin-bottom: var(--spacing-lg);
}

.checkbox-label {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    cursor: pointer;
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.5;
}

.checkbox-label input[type="checkbox"] {
    display: none;
}

.checkmark {
    flex-shrink: 0;
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-primary);
    border-radius: var(--radius-sm);
    position: relative;
    transition: var(--transition);
    margin-top: 2px;
}

.checkbox-label input[type="checkbox"]:checked + .checkmark {
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    border-color: var(--primary);
}

.checkbox-label input[type="checkbox"]:checked + .checkmark::after {
    content: '';
    position: absolute;
    left: 6px;
    top: 2px;
    width: 5px;
    height: 10px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

/* ========== TOAST ========== */
.toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: linear-gradient(135deg, var(--surface), var(--surface-light));
    color: white;
    padding: 14px 24px;
    border-radius: 50px;
    box-shadow: 
        0 10px 25px rgba(0, 0, 0, 0.5),
        0 0 20px rgba(6, 182, 212, 0.3);
    border: 1px solid var(--border-primary);
    font-size: 14px;
    opacity: 0;
    transition: var(--transition-bounce);
    z-index: 1000;
    display: flex;
    align-items: center;
    gap: 10px;
    max-width: 90%;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

/* ========== LOADER ========== */
.loader {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ========== NAVIGATION ========== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-primary);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 700;
    color: var(--text-bright);
    text-decoration: none;
}

.logo i {
    color: var(--primary);
    font-size: 24px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 16px;
}

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    transition: var(--transition);
}

.nav-link:hover {
    color: var(--primary);
}

.btn-nav {
    padding: 10px 20px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: white;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 14px;
    transition: var(--transition);
}

.btn-nav:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(6, 182, 212, 0.4);
    color: white;
}